20312431 has 4 divisors (see below), whose sum is σ = 20336832. Its totient is φ = 20288032.

The previous prime is 20312429. The next prime is 20312437. The reversal of 20312431 is 13421302.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20312431 - 2¹ = 20312429 is a prime.

It is a super-2 number, since 2×20312431² = 825189706259522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20312437) 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, 10906 + ... + 12631.

It is an arithmetic number, because the mean of its divisors is an integer number (5084208).

Almost surely, 2^20312431 is an apocalyptic number.

20312431 is a deficient number, since it is larger than the sum of its proper divisors (24401).

20312431 is an equidigital number, since it uses as much as digits as its factorization.

20312431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24400.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 20312431 is about 4506.9314394608. The cubic root of 20312431 is about 272.8479118168.

Adding to 20312431 its reverse (13421302), we get a palindrome (33733733).

The spelling of 20312431 in words is "twenty million, three hundred twelve thousand, four hundred thirty-one".