21202321020 has 48 divisors (see below), whose sum is σ = 59472040320. Its totient is φ = 5643900736.

The previous prime is 21202320991. The next prime is 21202321043. The reversal of 21202321020 is 2012320212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 280050 + ... + 347609.

It is an arithmetic number, because the mean of its divisors is an integer number (1239000840).

Almost surely, 2^21202321020 is an apocalyptic number.

21202321020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202321020 is an abundant number, since it is smaller than the sum of its proper divisors (38269719300).

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

21202321020 is a wasteful number, since it uses less digits than its factorization.

21202321020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628234 (or 628232 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21202321020 its reverse (2012320212), we get a palindrome (23214641232).

The spelling of 21202321020 in words is "twenty-one billion, two hundred two million, three hundred twenty-one thousand, twenty".