1251012521 has 16 divisors (see below), whose sum is σ = 1374252480. Its totient is φ = 1129390080.

The previous prime is 1251012509. The next prime is 1251012523. The reversal of 1251012521 is 1252101521.

It is a cyclic number.

It is not a de Polignac number, because 1251012521 - 2⁶ = 1251012457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1251012493 and 1251012502.

It is not an unprimeable number, because it can be changed into a prime (1251012523) 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, 1545965 + ... + 1546773.

It is an arithmetic number, because the mean of its divisors is an integer number (85890780).

Almost surely, 2^1251012521 is an apocalyptic number.

1251012521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1251012521 is a deficient number, since it is larger than the sum of its proper divisors (123239959).

1251012521 is a wasteful number, since it uses less digits than its factorization.

1251012521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1624.

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 1251012521 is about 35369.6553701050. The cubic root of 1251012521 is about 1077.5081212344.

The spelling of 1251012521 in words is "one billion, two hundred fifty-one million, twelve thousand, five hundred twenty-one".