20400312131 has 8 divisors (see below), whose sum is σ = 21139740720. Its totient is φ = 19663281568.

The previous prime is 20400312091. The next prime is 20400312169. The reversal of 20400312131 is 13121300402.

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

It is a de Polignac number, because none of the positive numbers 2^k-20400312131 is a prime.

It is a super-2 number, since 2×20400312131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20400317131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 582176 + ... + 616221.

It is an arithmetic number, because the mean of its divisors is an integer number (2642467590).

Almost surely, 2^20400312131 is an apocalyptic number.

20400312131 is a deficient number, since it is larger than the sum of its proper divisors (739428589).

20400312131 is a wasteful number, since it uses less digits than its factorization.

20400312131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1199013.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 20400312131 its reverse (13121300402), we get a palindrome (33521612533).

The spelling of 20400312131 in words is "twenty billion, four hundred million, three hundred twelve thousand, one hundred thirty-one".