23642581 has 2 divisors, whose sum is σ = 23642582. Its totient is φ = 23642580.

The previous prime is 23642579. The next prime is 23642587. The reversal of 23642581 is 18524632.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22953681 + 688900 = 4791^2 + 830^2 .

It is a cyclic number.

It is not a de Polignac number, because 23642581 - 2¹ = 23642579 is a prime.

It is a super-2 number, since 2×23642581² = 1117943272683122, which contains 22 as substring.

Together with 23642579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23642587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11821290 + 11821291.

It is an arithmetic number, because the mean of its divisors is an integer number (11821291).

Almost surely, 2^23642581 is an apocalyptic number.

It is an amenable number.

23642581 is a deficient number, since it is larger than the sum of its proper divisors (1).

23642581 is an equidigital number, since it uses as much as digits as its factorization.

23642581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 31.

The square root of 23642581 is about 4862.3637255968. The cubic root of 23642581 is about 287.0108370013.

The spelling of 23642581 in words is "twenty-three million, six hundred forty-two thousand, five hundred eighty-one".