1312135021 has 8 divisors (see below), whose sum is σ = 1389723264. Its totient is φ = 1234591680.

The previous prime is 1312135009. The next prime is 1312135039. The reversal of 1312135021 is 1205312131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1312135021 - 2⁷ = 1312134893 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1312135021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312135001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63036 + ... + 81226.

It is an arithmetic number, because the mean of its divisors is an integer number (173715408).

Almost surely, 2^1312135021 is an apocalyptic number.

It is an amenable number.

1312135021 is a deficient number, since it is larger than the sum of its proper divisors (77588243).

1312135021 is a wasteful number, since it uses less digits than its factorization.

1312135021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22451.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1312135021 is about 36223.4043264848. The cubic root of 1312135021 is about 1094.7782877845.

Adding to 1312135021 its reverse (1205312131), we get a palindrome (2517447152).

The spelling of 1312135021 in words is "one billion, three hundred twelve million, one hundred thirty-five thousand, twenty-one".