1312371561 has 4 divisors (see below), whose sum is σ = 1749828752. Its totient is φ = 874914372.

The previous prime is 1312371527. The next prime is 1312371563. The reversal of 1312371561 is 1651732131.

1312371561 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1312371561 - 2⁷ = 1312371433 is a prime.

It is a super-2 number, since 2×1312371561² = 3444638228243153442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1312371563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218728591 + ... + 218728596.

It is an arithmetic number, because the mean of its divisors is an integer number (437457188).

Almost surely, 2^1312371561 is an apocalyptic number.

It is an amenable number.

1312371561 is a deficient number, since it is larger than the sum of its proper divisors (437457191).

1312371561 is an equidigital number, since it uses as much as digits as its factorization.

1312371561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437457190.

The product of its digits is 3780, while the sum is 30.

The square root of 1312371561 is about 36226.6691954974. The cubic root of 1312371561 is about 1094.8440694540.

The spelling of 1312371561 in words is "one billion, three hundred twelve million, three hundred seventy-one thousand, five hundred sixty-one".