20311431 has 16 divisors (see below), whose sum is σ = 31584000. Its totient is φ = 11605944.

The previous prime is 20311381. The next prime is 20311433. The reversal of 20311431 is 13411302.

It is not a de Polignac number, because 20311431 - 2⁹ = 20310919 is a prime.

It is a super-2 number, since 2×20311431² = 825108458535522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20311431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20311433) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8841 + ... + 10898.

It is an arithmetic number, because the mean of its divisors is an integer number (1974000).

Almost surely, 2^20311431 is an apocalyptic number.

20311431 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20311431 is a deficient number, since it is larger than the sum of its proper divisors (11272569).

20311431 is an equidigital number, since it uses as much as digits as its factorization.

20311431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19763 (or 19749 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 20311431 is about 4506.8204978676. The cubic root of 20311431 is about 272.8434342239.

Adding to 20311431 its reverse (13411302), we get a palindrome (33722733).

The spelling of 20311431 in words is "twenty million, three hundred eleven thousand, four hundred thirty-one".