21731437131 has 32 divisors (see below), whose sum is σ = 31507660800. Its totient is φ = 13272452640.

The previous prime is 21731437121. The next prime is 21731437151. The reversal of 21731437131 is 13173413712.

It is not a de Polignac number, because 21731437131 - 2⁷ = 21731437003 is a prime.

It is a super-2 number, since 2×21731437131² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21731437092 and 21731437101.

It is not an unprimeable number, because it can be changed into a prime (21731437121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2871130 + ... + 2878688.

It is an arithmetic number, because the mean of its divisors is an integer number (984614400).

Almost surely, 2^21731437131 is an apocalyptic number.

21731437131 is a deficient number, since it is larger than the sum of its proper divisors (9776223669).

21731437131 is a wasteful number, since it uses less digits than its factorization.

21731437131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9239.

The product of its digits is 10584, while the sum is 33.

The spelling of 21731437131 in words is "twenty-one billion, seven hundred thirty-one million, four hundred thirty-seven thousand, one hundred thirty-one".