21210131131 has 32 divisors (see below), whose sum is σ = 25042160000. Its totient is φ = 17955374976.

The previous prime is 21210131123. The next prime is 21210131161. The reversal of 21210131131 is 13113101212.

It is a happy number.

It is not a de Polignac number, because 21210131131 - 2³ = 21210131123 is a prime.

It is a super-2 number, since 2×21210131131² (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 (21210131161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14841925 + ... + 14843353.

It is an arithmetic number, because the mean of its divisors is an integer number (782567500).

Almost surely, 2^21210131131 is an apocalyptic number.

21210131131 is a deficient number, since it is larger than the sum of its proper divisors (3832028869).

21210131131 is a wasteful number, since it uses less digits than its factorization.

21210131131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1956 (or 1942 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21210131131 its reverse (13113101212), we get a palindrome (34323232343).

The spelling of 21210131131 in words is "twenty-one billion, two hundred ten million, one hundred thirty-one thousand, one hundred thirty-one".