23556821957 has 2 divisors, whose sum is σ = 23556821958. Its totient is φ = 23556821956.

The previous prime is 23556821941. The next prime is 23556821989. The reversal of 23556821957 is 75912865532.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22796772196 + 760049761 = 150986^2 + 27569^2 .

It is a cyclic number.

It is not a de Polignac number, because 23556821957 - 2⁴ = 23556821941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 23556821899 and 23556821908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23556821917) 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 as a sum of consecutive naturals, namely, 11778410978 + 11778410979.

It is an arithmetic number, because the mean of its divisors is an integer number (11778410979).

Almost surely, 2^23556821957 is an apocalyptic number.

It is an amenable number.

23556821957 is a deficient number, since it is larger than the sum of its proper divisors (1).

23556821957 is an equidigital number, since it uses as much as digits as its factorization.

23556821957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536000, while the sum is 53.

The spelling of 23556821957 in words is "twenty-three billion, five hundred fifty-six million, eight hundred twenty-one thousand, nine hundred fifty-seven".