21130320131 has 4 divisors (see below), whose sum is σ = 21208292064. Its totient is φ = 21052348200.

The previous prime is 21130320061. The next prime is 21130320143. The reversal of 21130320131 is 13102303112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21130320131 is a prime.

It is a super-2 number, since 2×21130320131² (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 (21130320331) 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, 38985560 + ... + 38986101.

It is an arithmetic number, because the mean of its divisors is an integer number (5302073016).

Almost surely, 2^21130320131 is an apocalyptic number.

21130320131 is a deficient number, since it is larger than the sum of its proper divisors (77971933).

21130320131 is an equidigital number, since it uses as much as digits as its factorization.

21130320131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77971932.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21130320131 its reverse (13102303112), we get a palindrome (34232623243).

The spelling of 21130320131 in words is "twenty-one billion, one hundred thirty million, three hundred twenty thousand, one hundred thirty-one".