1251591125 has 16 divisors (see below), whose sum is σ = 1565868720. Its totient is φ = 998784000.

The previous prime is 1251591073. The next prime is 1251591127. The reversal of 1251591125 is 5211951521.

It can be written as a sum of positive squares in 8 ways, for example, as 525234724 + 726356401 = 22918^2 + 26951^2 .

It is not a de Polignac number, because 1251591125 - 2¹⁰ = 1251590101 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1251591091 and 1251591100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251591127) 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, 38885 + ... + 63365.

It is an arithmetic number, because the mean of its divisors is an integer number (97866795).

Almost surely, 2^1251591125 is an apocalyptic number.

It is an amenable number.

1251591125 is a deficient number, since it is larger than the sum of its proper divisors (314277595).

1251591125 is an equidigital number, since it uses as much as digits as its factorization.

1251591125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24905 (or 24895 counting only the distinct ones).

The product of its digits is 4500, while the sum is 32.

The square root of 1251591125 is about 35377.8338087566. The cubic root of 1251591125 is about 1077.6742145405.

The spelling of 1251591125 in words is "one billion, two hundred fifty-one million, five hundred ninety-one thousand, one hundred twenty-five".