21255616145360 has 80 divisors (see below), whose sum is σ = 49484395920960. Its totient is φ = 8491052021760.

The previous prime is 21255616145299. The next prime is 21255616145461. The reversal of 21255616145360 is 6354161655212.

It is a happy number.

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 polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 437163131 + ... + 437211749.

It is an arithmetic number, because the mean of its divisors is an integer number (618554949012).

Almost surely, 2^{21255616145360} is an apocalyptic number.

21255616145360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21255616145360 is an abundant number, since it is smaller than the sum of its proper divisors (28228779775600).

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

21255616145360 is a wasteful number, since it uses less digits than its factorization.

21255616145360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55716 (or 55710 counting only the distinct ones).

The product of its (nonzero) digits is 1296000, while the sum is 47.

The spelling of 21255616145360 in words is "twenty-one trillion, two hundred fifty-five billion, six hundred sixteen million, one hundred forty-five thousand, three hundred sixty".