21031312130 has 16 divisors (see below), whose sum is σ = 38570633784. Its totient is φ = 8253797760.

The previous prime is 21031312129. The next prime is 21031312157. The reversal of 21031312130 is 3121313012.

It can be written as a sum of positive squares in 4 ways, for example, as 19236857809 + 1794454321 = 138697^2 + 42361^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21031312099 and 21031312108.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19840331 + ... + 19841390.

Almost surely, 2^21031312130 is an apocalyptic number.

21031312130 is a deficient number, since it is larger than the sum of its proper divisors (17539321654).

21031312130 is a wasteful number, since it uses less digits than its factorization.

21031312130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39681781.

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

Adding to 21031312130 its reverse (3121313012), we get a palindrome (24152625142).

The spelling of 21031312130 in words is "twenty-one billion, thirty-one million, three hundred twelve thousand, one hundred thirty".