25537857617 has 2 divisors, whose sum is σ = 25537857618. Its totient is φ = 25537857616.

The previous prime is 25537857607. The next prime is 25537857637. The reversal of 25537857617 is 71675873552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12885882256 + 12651975361 = 113516^2 + 112481^2 .

It is a cyclic number.

It is not a de Polignac number, because 25537857617 - 2⁸ = 25537857361 is a prime.

It is not a weakly prime, because it can be changed into another prime (25537857607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12768928808 + 12768928809.

It is an arithmetic number, because the mean of its divisors is an integer number (12768928809).

Almost surely, 2^25537857617 is an apocalyptic number.

It is an amenable number.

25537857617 is a deficient number, since it is larger than the sum of its proper divisors (1).

25537857617 is an equidigital number, since it uses as much as digits as its factorization.

25537857617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12348000, while the sum is 56.

The spelling of 25537857617 in words is "twenty-five billion, five hundred thirty-seven million, eight hundred fifty-seven thousand, six hundred seventeen".