1231213431 has 8 divisors (see below), whose sum is σ = 1876134784. Its totient is φ = 703550520.

The previous prime is 1231213427. The next prime is 1231213441. The reversal of 1231213431 is 1343121321.

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

It is not a de Polignac number, because 1231213431 - 2² = 1231213427 is a prime.

It is a super-2 number, since 2×1231213431² = 3031773025349583522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 58629211 = 1231213431 / (1 + 2 + 3 + 1 + 2 + 1 + 3 + 4 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1231213398 and 1231213407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231213411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29314585 + ... + 29314626.

It is an arithmetic number, because the mean of its divisors is an integer number (234516848).

Almost surely, 2^1231213431 is an apocalyptic number.

1231213431 is a deficient number, since it is larger than the sum of its proper divisors (644921353).

1231213431 is an equidigital number, since it uses as much as digits as its factorization.

1231213431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58629221.

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

The square root of 1231213431 is about 35088.6510285021. The cubic root of 1231213431 is about 1071.7934899482.

Adding to 1231213431 its reverse (1343121321), we get a palindrome (2574334752).

The spelling of 1231213431 in words is "one billion, two hundred thirty-one million, two hundred thirteen thousand, four hundred thirty-one".