23186640 has 80 divisors (see below), whose sum is σ = 76120128. Its totient is φ = 5818368.

The previous prime is 23186633. The next prime is 23186641. The reversal of 23186640 is 4668132.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 23186598 and 23186607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23186641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1239 + ... + 6921.

Almost surely, 2^23186640 is an apocalyptic number.

23186640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 23186640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38060064).

23186640 is an abundant number, since it is smaller than the sum of its proper divisors (52933488).

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

23186640 is a wasteful number, since it uses less digits than its factorization.

23186640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5716 (or 5710 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 23186640 is about 4815.2507722859. The cubic root of 23186640 is about 285.1538719724.

The spelling of 23186640 in words is "twenty-three million, one hundred eighty-six thousand, six hundred forty".