21044554420 has 24 divisors (see below), whose sum is σ = 44247297024. Its totient is φ = 8407586976.

The previous prime is 21044554403. The next prime is 21044554471. The reversal of 21044554420 is 2445544012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 622804 + ... + 655723.

It is an arithmetic number, because the mean of its divisors is an integer number (1843637376).

Almost surely, 2^21044554420 is an apocalyptic number.

21044554420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21044554420 is an abundant number, since it is smaller than the sum of its proper divisors (23202742604).

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

21044554420 is a wasteful number, since it uses less digits than its factorization.

21044554420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1279359 (or 1279357 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 31.

The spelling of 21044554420 in words is "twenty-one billion, forty-four million, five hundred fifty-four thousand, four hundred twenty".