21980678500 has 72 divisors (see below), whose sum is σ = 52766853048. Its totient is φ = 7992952000.

The previous prime is 21980678497. The next prime is 21980678549. The reversal of 21980678500 is 587608912.

It can be written as a sum of positive squares in 4 ways, for example, as 234457344 + 21746221156 = 15312^2 + 147466^2 .

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 121159 + ... + 242158.

It is an arithmetic number, because the mean of its divisors is an integer number (732872959).

Almost surely, 2^21980678500 is an apocalyptic number.

21980678500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21980678500 is an abundant number, since it is smaller than the sum of its proper divisors (30786174548).

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

21980678500 is a wasteful number, since it uses less digits than its factorization.

21980678500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363358 (or 363335 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 46.

The spelling of 21980678500 in words is "twenty-one billion, nine hundred eighty million, six hundred seventy-eight thousand, five hundred".