21387154320 has 480 divisors, whose sum is σ = 85641304320. Its totient is φ = 4679700480.

The previous prime is 21387154301. The next prime is 21387154337. The reversal of 21387154320 is 2345178312.

21387154320 is a `hidden beast` number, since 2 + 13 + 87 + 1 + 543 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 19146402 + ... + 19147518.

It is an arithmetic number, because the mean of its divisors is an integer number (178419384).

Almost surely, 2^21387154320 is an apocalyptic number.

21387154320 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 21387154320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42820652160).

21387154320 is an abundant number, since it is smaller than the sum of its proper divisors (64254150000).

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

21387154320 is a wasteful number, since it uses less digits than its factorization.

21387154320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1303 (or 1294 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 21387154320 in words is "twenty-one billion, three hundred eighty-seven million, one hundred fifty-four thousand, three hundred twenty".