21020231312 has 20 divisors (see below), whose sum is σ = 40729395756. Its totient is φ = 10509419520.

The previous prime is 21020231299. The next prime is 21020231359. The reversal of 21020231312 is 21313202012.

It can be written as a sum of positive squares in 2 ways, for example, as 6777240976 + 14242990336 = 82324^2 + 119344^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 277268 + ... + 344844.

Almost surely, 2^21020231312 is an apocalyptic number.

It is an amenable number.

21020231312 is a deficient number, since it is larger than the sum of its proper divisors (19709164444).

21020231312 is a wasteful number, since it uses less digits than its factorization.

21020231312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87026 (or 87020 counting only the distinct ones).

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

Adding to 21020231312 its reverse (21313202012), we get a palindrome (42333433324).

The spelling of 21020231312 in words is "twenty-one billion, twenty million, two hundred thirty-one thousand, three hundred twelve".