21044533554 has 24 divisors (see below), whose sum is σ = 49741625232. Its totient is φ = 6377131320.

The previous prime is 21044533469. The next prime is 21044533571. The reversal of 21044533554 is 45533544012.

21044533554 is a `hidden beast` number, since 2 + 10 + 44 + 53 + 3 + 554 = 666.

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, 53142564 + ... + 53142959.

It is an arithmetic number, because the mean of its divisors is an integer number (2072567718).

Almost surely, 2^21044533554 is an apocalyptic number.

21044533554 is an abundant number, since it is smaller than the sum of its proper divisors (28697091678).

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

21044533554 is a wasteful number, since it uses less digits than its factorization.

21044533554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106285542 (or 106285539 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 36.

The spelling of 21044533554 in words is "twenty-one billion, forty-four million, five hundred thirty-three thousand, five hundred fifty-four".