25015319981 has 2 divisors, whose sum is σ = 25015319982. Its totient is φ = 25015319980.

The previous prime is 25015319933. The next prime is 25015320019. The reversal of 25015319981 is 18991351052.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23828861956 + 1186458025 = 154366^2 + 34445^2 .

It is a cyclic number.

It is not a de Polignac number, because 25015319981 - 2¹⁴ = 25015303597 is a prime.

It is a super-2 number, since 2×25015319981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25015319911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12507659990 + 12507659991.

It is an arithmetic number, because the mean of its divisors is an integer number (12507659991).

Almost surely, 2^25015319981 is an apocalyptic number.

It is an amenable number.

25015319981 is a deficient number, since it is larger than the sum of its proper divisors (1).

25015319981 is an equidigital number, since it uses as much as digits as its factorization.

25015319981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 97200, while the sum is 44.

The spelling of 25015319981 in words is "twenty-five billion, fifteen million, three hundred nineteen thousand, nine hundred eighty-one".