21929943220 has 48 divisors (see below), whose sum is σ = 48781389888. Its totient is φ = 8252674560.

The previous prime is 21929943209. The next prime is 21929943221. The reversal of 21929943220 is 2234992912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21929943221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 941515 + ... + 964525.

It is an arithmetic number, because the mean of its divisors is an integer number (1016278956).

Almost surely, 2^21929943220 is an apocalyptic number.

21929943220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21929943220 is an abundant number, since it is smaller than the sum of its proper divisors (26851446668).

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

21929943220 is a wasteful number, since it uses less digits than its factorization.

21929943220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25840 (or 25838 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 21929943220 in words is "twenty-one billion, nine hundred twenty-nine million, nine hundred forty-three thousand, two hundred twenty".