25497194981 has 2 divisors, whose sum is σ = 25497194982. Its totient is φ = 25497194980.

The previous prime is 25497194971. The next prime is 25497195013. The reversal of 25497194981 is 18949179452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25451416225 + 45778756 = 159535^2 + 6766^2 .

It is a cyclic number.

It is not a de Polignac number, because 25497194981 - 2¹⁸ = 25496932837 is a prime.

It is a super-2 number, since 2×25497194981² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25497194981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25497194971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12748597490 + 12748597491.

It is an arithmetic number, because the mean of its divisors is an integer number (12748597491).

Almost surely, 2^25497194981 is an apocalyptic number.

It is an amenable number.

25497194981 is a deficient number, since it is larger than the sum of its proper divisors (1).

25497194981 is an equidigital number, since it uses as much as digits as its factorization.

25497194981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6531840, while the sum is 59.

The spelling of 25497194981 in words is "twenty-five billion, four hundred ninety-seven million, one hundred ninety-four thousand, nine hundred eighty-one".