23661520 has 20 divisors (see below), whose sum is σ = 55013220. Its totient is φ = 9464576.

The previous prime is 23661511. The next prime is 23661529. The reversal of 23661520 is 2516632.

It is an interprime number because it is at equal distance from previous prime (23661511) and next prime (23661529).

It can be written as a sum of positive squares in 2 ways, for example, as 3519376 + 20142144 = 1876^2 + 4488^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23661529) 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 3 ways as a sum of consecutive naturals, for example, 147805 + ... + 147964.

It is an arithmetic number, because the mean of its divisors is an integer number (2750661).

Almost surely, 2^23661520 is an apocalyptic number.

23661520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23661520 is an abundant number, since it is smaller than the sum of its proper divisors (31351700).

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

23661520 is a wasteful number, since it uses less digits than its factorization.

23661520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295782 (or 295776 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 23661520 is about 4864.3108453305. The cubic root of 23661520 is about 287.0874536710.

The spelling of 23661520 in words is "twenty-three million, six hundred sixty-one thousand, five hundred twenty".