1312021331 has 4 divisors (see below), whose sum is σ = 1317511200. Its totient is φ = 1306531464.

The previous prime is 1312021327. The next prime is 1312021351. The reversal of 1312021331 is 1331202131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1331202131 = 7 ⋅190171733.

It is a cyclic number.

It is not a de Polignac number, because 1312021331 - 2² = 1312021327 is a prime.

It is a super-2 number, since 2×1312021331² = 3442799945998023122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1312021351) 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, 2744576 + ... + 2745053.

It is an arithmetic number, because the mean of its divisors is an integer number (329377800).

Almost surely, 2^1312021331 is an apocalyptic number.

1312021331 is a deficient number, since it is larger than the sum of its proper divisors (5489869).

1312021331 is an equidigital number, since it uses as much as digits as its factorization.

1312021331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5489868.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1312021331 is about 36221.8350032132. The cubic root of 1312021331 is about 1094.7466678327.

Adding to 1312021331 its reverse (1331202131), we get a palindrome (2643223462).

The spelling of 1312021331 in words is "one billion, three hundred twelve million, twenty-one thousand, three hundred thirty-one".