25630177921 has 2 divisors, whose sum is σ = 25630177922. Its totient is φ = 25630177920.

The previous prime is 25630177919. The next prime is 25630178009. The reversal of 25630177921 is 12977103652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25628487921 + 1690000 = 160089^2 + 1300^2 .

It is a cyclic number.

It is not a de Polignac number, because 25630177921 - 2¹ = 25630177919 is a prime.

Together with 25630177919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (25630177421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12815088960 + 12815088961.

It is an arithmetic number, because the mean of its divisors is an integer number (12815088961).

Almost surely, 2^25630177921 is an apocalyptic number.

It is an amenable number.

25630177921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25630177921 is an equidigital number, since it uses as much as digits as its factorization.

25630177921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 158760, while the sum is 43.

The spelling of 25630177921 in words is "twenty-five billion, six hundred thirty million, one hundred seventy-seven thousand, nine hundred twenty-one".