21023313320 has 16 divisors (see below), whose sum is σ = 47302455060. Its totient is φ = 8409325312.

The previous prime is 21023313319. The next prime is 21023313343. The reversal of 21023313320 is 2331332012.

It can be written as a sum of positive squares in 2 ways, for example, as 19695876964 + 1327436356 = 140342^2 + 36434^2 .

It is a super-3 number, since 3×21023313320³ (a number of 32 digits) contains 333 as substring.

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 = 21023313292 and 21023313301.

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, 262791377 + ... + 262791456.

Almost surely, 2^21023313320 is an apocalyptic number.

21023313320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21023313320 is an abundant number, since it is smaller than the sum of its proper divisors (26279141740).

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

21023313320 is a wasteful number, since it uses less digits than its factorization.

21023313320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525582844 (or 525582840 counting only the distinct ones).

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

Adding to 21023313320 its reverse (2331332012), we get a palindrome (23354645332).

The spelling of 21023313320 in words is "twenty-one billion, twenty-three million, three hundred thirteen thousand, three hundred twenty".