23559981 has 16 divisors (see below), whose sum is σ = 34506240. Its totient is φ = 14232240.

The previous prime is 23559979. The next prime is 23559983. The reversal of 23559981 is 18995532.

It is an interprime number because it is at equal distance from previous prime (23559979) and next prime (23559983).

It is not a de Polignac number, because 23559981 - 2¹ = 23559979 is a prime.

It is a super-2 number, since 2×23559981² = 1110145409440722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23559983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7675 + ... + 10296.

It is an arithmetic number, because the mean of its divisors is an integer number (2156640).

Almost surely, 2^23559981 is an apocalyptic number.

It is an amenable number.

23559981 is a deficient number, since it is larger than the sum of its proper divisors (10946259).

23559981 is a wasteful number, since it uses less digits than its factorization.

23559981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18016.

The product of its digits is 97200, while the sum is 42.

The square root of 23559981 is about 4853.8624826008. The cubic root of 23559981 is about 286.6762040875.

The spelling of 23559981 in words is "twenty-three million, five hundred fifty-nine thousand, nine hundred eighty-one".