25647500297981 has 2 divisors, whose sum is σ = 25647500297982. Its totient is φ = 25647500297980.

The previous prime is 25647500297807. The next prime is 25647500297983. The reversal of 25647500297981 is 18979200574652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25612364669956 + 35135628025 = 5060866^2 + 187445^2 .

It is a cyclic number.

It is not a de Polignac number, because 25647500297981 - 2²⁶ = 25647433189117 is a prime.

It is a super-2 number, since 2×25647500297981² (a number of 28 digits) contains 22 as substring.

Together with 25647500297983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25647500297983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12823750148990 + 12823750148991.

It is an arithmetic number, because the mean of its divisors is an integer number (12823750148991).

Almost surely, 2^{25647500297981} is an apocalyptic number.

It is an amenable number.

25647500297981 is a deficient number, since it is larger than the sum of its proper divisors (1).

25647500297981 is an equidigital number, since it uses as much as digits as its factorization.

25647500297981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 76204800, while the sum is 65.

The spelling of 25647500297981 in words is "twenty-five trillion, six hundred forty-seven billion, five hundred million, two hundred ninety-seven thousand, nine hundred eighty-one".