21550354015440 has 80 divisors (see below), whose sum is σ = 66819151872000. Its totient is φ = 5745638109696.

The previous prime is 21550354015423. The next prime is 21550354015451. The reversal of 21550354015440 is 4451045305512.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 7542015 + ... + 9999134.

It is an arithmetic number, because the mean of its divisors is an integer number (835239398400).

Almost surely, 2^{21550354015440} is an apocalyptic number.

21550354015440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21550354015440 is an abundant number, since it is smaller than the sum of its proper divisors (45268797856560).

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

21550354015440 is a wasteful number, since it uses less digits than its factorization.

21550354015440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17546284 (or 17546278 counting only the distinct ones).

The product of its (nonzero) digits is 240000, while the sum is 39.

The spelling of 21550354015440 in words is "twenty-one trillion, five hundred fifty billion, three hundred fifty-four million, fifteen thousand, four hundred forty".