23490 has 40 divisors (see below), whose sum is σ = 65340. Its totient is φ = 6048.

The previous prime is 23473. The next prime is 23497. The reversal of 23490 is 9432.

23490 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 23409 + 81 = 153^2 + 9^2 .

23490 is an astonishing number since 23490 = 90 + ... + 234.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (23497) by changing a digit.

23490 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 796 + ... + 824.

23490 is a Friedman number, since it can be written as 290*3^4, using all its digits and the basic arithmetic operations.

2^{23490} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 23490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32670).

23490 is an abundant number, since it is smaller than the sum of its proper divisors (41850).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

23490 is a wasteful number, since it uses less digits than its factorization.

23490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48 (or 39 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 23490 is about 153.2644772933. The cubic root of 23490 is about 28.6392081281.

It can be divided in two parts, 234 and 90, that added together give a square (324 = 18^{2}).

The spelling of 23490 in words is "twenty-three thousand, four hundred ninety".

Divisors: 1 2 3 5 6 9 10 15 18 27 29 30 45 54 58 81 87 90 135 145 162 174 261 270 290 405 435 522 783 810 870 1305 1566 2349 2610 3915 4698 7830 11745 23490

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