1321511431 has 4 divisors (see below), whose sum is σ = 1364140864. Its totient is φ = 1278882000.

The previous prime is 1321511423. The next prime is 1321511449. The reversal of 1321511431 is 1341151231.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1341151231 = 7 ⋅191593033.

It is a cyclic number.

It is not a de Polignac number, because 1321511431 - 2³ = 1321511423 is a prime.

It is a super-2 number, since 2×1321511431² = 3492784924527335522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321511461) 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, 21314670 + ... + 21314731.

It is an arithmetic number, because the mean of its divisors is an integer number (341035216).

Almost surely, 2^1321511431 is an apocalyptic number.

1321511431 is a deficient number, since it is larger than the sum of its proper divisors (42629433).

1321511431 is an equidigital number, since it uses as much as digits as its factorization.

1321511431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42629432.

The product of its digits is 360, while the sum is 22.

The square root of 1321511431 is about 36352.5986829002. The cubic root of 1321511431 is about 1097.3798329420.

Adding to 1321511431 its reverse (1341151231), we get a palindrome (2662662662).

The spelling of 1321511431 in words is "one billion, three hundred twenty-one million, five hundred eleven thousand, four hundred thirty-one".