21260072220 has 96 divisors (see below), whose sum is σ = 59854648896. Its totient is φ = 5638348800.

The previous prime is 21260072219. The next prime is 21260072257. The reversal of 21260072220 is 2227006212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12829632 + ... + 12831288.

It is an arithmetic number, because the mean of its divisors is an integer number (623485926).

Almost surely, 2^21260072220 is an apocalyptic number.

21260072220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21260072220 is an abundant number, since it is smaller than the sum of its proper divisors (38594576676).

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

21260072220 is a wasteful number, since it uses less digits than its factorization.

21260072220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2711 (or 2709 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

Adding to 21260072220 its reverse (2227006212), we get a palindrome (23487078432).

The spelling of 21260072220 in words is "twenty-one billion, two hundred sixty million, seventy-two thousand, two hundred twenty".