21971844080 has 60 divisors (see below), whose sum is σ = 51314866680. Its totient is φ = 8749287936.

The previous prime is 21971844077. The next prime is 21971844121. The reversal of 21971844080 is 8044817912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4340591 + ... + 4345649.

It is an arithmetic number, because the mean of its divisors is an integer number (855247778).

Almost surely, 2^21971844080 is an apocalyptic number.

21971844080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21971844080 is an abundant number, since it is smaller than the sum of its proper divisors (29343022600).

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

21971844080 is an equidigital number, since it uses as much as digits as its factorization.

21971844080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5538 (or 5299 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 44.

The spelling of 21971844080 in words is "twenty-one billion, nine hundred seventy-one million, eight hundred forty-four thousand, eighty".