25518514321 has 2 divisors, whose sum is σ = 25518514322. Its totient is φ = 25518514320.

The previous prime is 25518514279. The next prime is 25518514331. The reversal of 25518514321 is 12341581552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25459393600 + 59120721 = 159560^2 + 7689^2 .

It is a cyclic number.

It is not a de Polignac number, because 25518514321 - 2²⁵ = 25484959889 is a prime.

It is not a weakly prime, because it can be changed into another prime (25518514331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12759257160 + 12759257161.

It is an arithmetic number, because the mean of its divisors is an integer number (12759257161).

Almost surely, 2^25518514321 is an apocalyptic number.

It is an amenable number.

25518514321 is a deficient number, since it is larger than the sum of its proper divisors (1).

25518514321 is an equidigital number, since it uses as much as digits as its factorization.

25518514321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48000, while the sum is 37.

The spelling of 25518514321 in words is "twenty-five billion, five hundred eighteen million, five hundred fourteen thousand, three hundred twenty-one".