25235628721 has 2 divisors, whose sum is σ = 25235628722. Its totient is φ = 25235628720.

The previous prime is 25235628689. The next prime is 25235628757. The reversal of 25235628721 is 12782653252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22184613025 + 3051015696 = 148945^2 + 55236^2 .

It is a cyclic number.

It is not a de Polignac number, because 25235628721 - 2⁵ = 25235628689 is a prime.

It is not a weakly prime, because it can be changed into another prime (25235628521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12617814360 + 12617814361.

It is an arithmetic number, because the mean of its divisors is an integer number (12617814361).

Almost surely, 2^25235628721 is an apocalyptic number.

It is an amenable number.

25235628721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25235628721 is an equidigital number, since it uses as much as digits as its factorization.

25235628721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 403200, while the sum is 43.

The spelling of 25235628721 in words is "twenty-five billion, two hundred thirty-five million, six hundred twenty-eight thousand, seven hundred twenty-one".