23618981 has 2 divisors, whose sum is σ = 23618982. Its totient is φ = 23618980.

The previous prime is 23618971. The next prime is 23618983. The reversal of 23618981 is 18981632.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14945956 + 8673025 = 3866^2 + 2945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23618981 is a prime.

It is a super-2 number, since 2×23618981² = 1115712526956722, which contains 22 as substring.

Together with 23618983, it forms a pair of twin primes.

It is a Chen prime.

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

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23618983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11809490 + 11809491.

It is an arithmetic number, because the mean of its divisors is an integer number (11809491).

Almost surely, 2^23618981 is an apocalyptic number.

It is an amenable number.

23618981 is a deficient number, since it is larger than the sum of its proper divisors (1).

23618981 is an equidigital number, since it uses as much as digits as its factorization.

23618981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 23618981 is about 4859.9363164552. The cubic root of 23618981 is about 286.9153072344.

The spelling of 23618981 in words is "twenty-three million, six hundred eighteen thousand, nine hundred eighty-one".