21031313020 has 48 divisors (see below), whose sum is σ = 47245917600. Its totient is φ = 7836033024.

The previous prime is 21031312997. The next prime is 21031313027. The reversal of 21031313020 is 2031313012.

It is a super-2 number, since 2×21031313020² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21031312985 and 21031313003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031313027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 285870 + ... + 351829.

It is an arithmetic number, because the mean of its divisors is an integer number (984289950).

Almost surely, 2^21031313020 is an apocalyptic number.

21031313020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21031313020 is an abundant number, since it is smaller than the sum of its proper divisors (26214604580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21031313020 is a wasteful number, since it uses less digits than its factorization.

21031313020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637822 (or 637820 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21031313020 its reverse (2031313012), we get a palindrome (23062626032).

The spelling of 21031313020 in words is "twenty-one billion, thirty-one million, three hundred thirteen thousand, twenty".