1251387637625 has 16 divisors (see below), whose sum is σ = 1561897698192. Its totient is φ = 1001003747200.

The previous prime is 1251387637603. The next prime is 1251387637627. The reversal of 1251387637625 is 5267367831521.

It can be written as a sum of positive squares in 8 ways, for example, as 740568676969 + 510818960656 = 860563^2 + 714716^2 .

It is not a de Polignac number, because 1251387637625 - 2⁶ = 1251387637561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1251387637627) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 660059 + ... + 1714191.

It is an arithmetic number, because the mean of its divisors is an integer number (97618606137).

Almost surely, 2^{1251387637625} is an apocalyptic number.

It is an amenable number.

1251387637625 is a deficient number, since it is larger than the sum of its proper divisors (310510060567).

1251387637625 is an equidigital number, since it uses as much as digits as its factorization.

1251387637625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063645 (or 1063635 counting only the distinct ones).

The product of its digits is 12700800, while the sum is 56.

The spelling of 1251387637625 in words is "one trillion, two hundred fifty-one billion, three hundred eighty-seven million, six hundred thirty-seven thousand, six hundred twenty-five".