23405720 has 128 divisors (see below), whose sum is σ = 62899200. Its totient is φ = 7755264.

The previous prime is 23405693. The next prime is 23405729. The reversal of 23405720 is 2750432.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23405729) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 227189 + ... + 227291.

It is an arithmetic number, because the mean of its divisors is an integer number (491400).

Almost surely, 2^23405720 is an apocalyptic number.

23405720 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 23405720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31449600).

23405720 is an abundant number, since it is smaller than the sum of its proper divisors (39493480).

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

23405720 is a wasteful number, since it uses less digits than its factorization.

23405720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 23.

The square root of 23405720 is about 4837.9458450876. The cubic root of 23405720 is about 286.0491545096.

The spelling of 23405720 in words is "twenty-three million, four hundred five thousand, seven hundred twenty".