21405455552 has 28 divisors (see below), whose sum is σ = 45743871936. Its totient is φ = 9879440640.

The previous prime is 21405455509. The next prime is 21405455567. The reversal of 21405455552 is 25555450412.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12863024 + ... + 12864687.

It is an arithmetic number, because the mean of its divisors is an integer number (1633709712).

Almost surely, 2^21405455552 is an apocalyptic number.

It is an amenable number.

21405455552 is an abundant number, since it is smaller than the sum of its proper divisors (24338416384).

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

21405455552 is a wasteful number, since it uses less digits than its factorization.

21405455552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25727736 (or 25727726 counting only the distinct ones).

The product of its (nonzero) digits is 200000, while the sum is 38.

The spelling of 21405455552 in words is "twenty-one billion, four hundred five million, four hundred fifty-five thousand, five hundred fifty-two".