20312231 has 4 divisors (see below), whose sum is σ = 20322432. Its totient is φ = 20302032.

The previous prime is 20312221. The next prime is 20312233. The reversal of 20312231 is 13221302.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20312231 is a prime.

It is a super-2 number, since 2×20312231² = 825173456394722, 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 (20312233) 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, 1031 + ... + 6456.

It is an arithmetic number, because the mean of its divisors is an integer number (5080608).

Almost surely, 2^20312231 is an apocalyptic number.

20312231 is a deficient number, since it is larger than the sum of its proper divisors (10201).

20312231 is an equidigital number, since it uses as much as digits as its factorization.

20312231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10200.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 20312231 is about 4506.9092513606. The cubic root of 20312231 is about 272.8470163100.

Adding to 20312231 its reverse (13221302), we get a palindrome (33533533).

The spelling of 20312231 in words is "twenty million, three hundred twelve thousand, two hundred thirty-one".