1251979160691 has 16 divisors (see below), whose sum is σ = 1907962550784. Its totient is φ = 715347369984.

The previous prime is 1251979160623. The next prime is 1251979160737. The reversal of 1251979160691 is 1960619791521.

It is a happy number.

It is not a de Polignac number, because 1251979160691 - 2⁷ = 1251979160563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1251979160891) 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, 2664846 + ... + 3099251.

It is an arithmetic number, because the mean of its divisors is an integer number (119247659424).

Almost surely, 2^{1251979160691} is an apocalyptic number.

1251979160691 is a deficient number, since it is larger than the sum of its proper divisors (655983390093).

1251979160691 is a wasteful number, since it uses less digits than its factorization.

1251979160691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5774450.

The product of its (nonzero) digits is 1837080, while the sum is 57.

The spelling of 1251979160691 in words is "one trillion, two hundred fifty-one billion, nine hundred seventy-nine million, one hundred sixty thousand, six hundred ninety-one".