21313023320 has 32 divisors (see below), whose sum is σ = 48014542800. Its totient is φ = 8514499968.

The previous prime is 21313023289. The next prime is 21313023353. The reversal of 21313023320 is 2332031312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21313023292 and 21313023301.

It is a congruent number.

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, 302390 + ... + 366149.

Almost surely, 2^21313023320 is an apocalyptic number.

21313023320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21313023320 is an abundant number, since it is smaller than the sum of its proper divisors (26701519480).

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

21313023320 is a wasteful number, since it uses less digits than its factorization.

21313023320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669347 (or 669343 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21313023320 its reverse (2332031312), we get a palindrome (23645054632).

The spelling of 21313023320 in words is "twenty-one billion, three hundred thirteen million, twenty-three thousand, three hundred twenty".