25456057721 has 2 divisors, whose sum is σ = 25456057722. Its totient is φ = 25456057720.

The previous prime is 25456057643. The next prime is 25456057729. The reversal of 25456057721 is 12775065452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18398209600 + 7057848121 = 135640^2 + 84011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25456057721 is a prime.

It is not a weakly prime, because it can be changed into another prime (25456057729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12728028860 + 12728028861.

It is an arithmetic number, because the mean of its divisors is an integer number (12728028861).

Almost surely, 2^25456057721 is an apocalyptic number.

It is an amenable number.

25456057721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25456057721 is an equidigital number, since it uses as much as digits as its factorization.

25456057721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 588000, while the sum is 44.

The spelling of 25456057721 in words is "twenty-five billion, four hundred fifty-six million, fifty-seven thousand, seven hundred twenty-one".