25257102721 has 2 divisors, whose sum is σ = 25257102722. Its totient is φ = 25257102720.

The previous prime is 25257102701. The next prime is 25257102797. The reversal of 25257102721 is 12720175252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25197117696 + 59985025 = 158736^2 + 7745^2 .

It is a cyclic number.

It is not a de Polignac number, because 25257102721 - 2¹⁵ = 25257069953 is a prime.

It is not a weakly prime, because it can be changed into another prime (25257102701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12628551360 + 12628551361.

It is an arithmetic number, because the mean of its divisors is an integer number (12628551361).

Almost surely, 2^25257102721 is an apocalyptic number.

It is an amenable number.

25257102721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25257102721 is an equidigital number, since it uses as much as digits as its factorization.

25257102721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19600, while the sum is 34.

Adding to 25257102721 its reverse (12720175252), we get a palindrome (37977277973).

The spelling of 25257102721 in words is "twenty-five billion, two hundred fifty-seven million, one hundred two thousand, seven hundred twenty-one".