1251378813925 has 18 divisors (see below), whose sum is σ = 1593691159254. Its totient is φ = 974019729600.

The previous prime is 1251378813847. The next prime is 1251378813931. The reversal of 1251378813925 is 5293188731521.

It can be written as a sum of positive squares in 9 ways, for example, as 898867063396 + 352511750529 = 948086^2 + 593727^2 .

It is not a de Polignac number, because 1251378813925 - 2⁹ = 1251378813413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 34004035 + ... + 34040815.

Almost surely, 2^{1251378813925} is an apocalyptic number.

It is an amenable number.

1251378813925 is a deficient number, since it is larger than the sum of its proper divisors (342312345329).

1251378813925 is an frugal number, since it uses more digits than its factorization.

1251378813925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73609 (or 36823 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 55.

The spelling of 1251378813925 in words is "one trillion, two hundred fifty-one billion, three hundred seventy-eight million, eight hundred thirteen thousand, nine hundred twenty-five".