1321431231 has 4 divisors (see below), whose sum is σ = 1761908312. Its totient is φ = 880954152.

The previous prime is 1321431211. The next prime is 1321431277. The reversal of 1321431231 is 1321341231.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1321431231 - 2¹¹ = 1321429183 is a prime.

It is a super-2 number, since 2×1321431231² = 3492360996524350722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321431198 and 1321431207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321431211) 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, 220238536 + ... + 220238541.

It is an arithmetic number, because the mean of its divisors is an integer number (440477078).

Almost surely, 2^1321431231 is an apocalyptic number.

1321431231 is a deficient number, since it is larger than the sum of its proper divisors (440477081).

1321431231 is an equidigital number, since it uses as much as digits as its factorization.

1321431231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440477080.

The product of its digits is 432, while the sum is 21.

The square root of 1321431231 is about 36351.4955813375. The cubic root of 1321431231 is about 1097.3576331988.

Adding to 1321431231 its reverse (1321341231), we get a palindrome (2642772462).

Subtracting from 1321431231 its reverse (1321341231), we obtain a square (90000 = 300²).

The spelling of 1321431231 in words is "one billion, three hundred twenty-one million, four hundred thirty-one thousand, two hundred thirty-one".