21903987879440 has 80 divisors (see below), whose sum is σ = 51578916238080. Its totient is φ = 8649430533120.

The previous prime is 21903987879413. The next prime is 21903987879463. The reversal of 21903987879440 is 4497878930912.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43808132 + ... + 44305308.

It is an arithmetic number, because the mean of its divisors is an integer number (644736452976).

Almost surely, 2^{21903987879440} is an apocalyptic number.

21903987879440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21903987879440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25789458119040).

21903987879440 is an abundant number, since it is smaller than the sum of its proper divisors (29674928358640).

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

21903987879440 is a wasteful number, since it uses less digits than its factorization.

21903987879440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504240 (or 504234 counting only the distinct ones).

The product of its (nonzero) digits is 219469824, while the sum is 71.

The spelling of 21903987879440 in words is "twenty-one trillion, nine hundred three billion, nine hundred eighty-seven million, eight hundred seventy-nine thousand, four hundred forty".