21538979900160 has 72 divisors (see below), whose sum is σ = 68790117068400. Its totient is φ = 5743727972352.

The previous prime is 21538979900153. The next prime is 21538979900219. The reversal of 21538979900160 is 6100997983512.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a junction number, because it is equal to n+sod(n) for n = 21538979900094 and 21538979900103.

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, 2804550835 + ... + 2804558514.

Almost surely, 2^{21538979900160} is an apocalyptic number.

21538979900160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21538979900160 is an abundant number, since it is smaller than the sum of its proper divisors (47251137168240).

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

21538979900160 is an equidigital number, since it uses as much as digits as its factorization.

21538979900160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5609109373 (or 5609109359 counting only the distinct ones).

The product of its (nonzero) digits is 7348320, while the sum is 60.

The spelling of 21538979900160 in words is "twenty-one trillion, five hundred thirty-eight billion, nine hundred seventy-nine million, nine hundred thousand, one hundred sixty".