21408877152 has 384 divisors, whose sum is σ = 72462297600. Its totient is φ = 6092900352.

The previous prime is 21408877129. The next prime is 21408877163. The reversal of 21408877152 is 25177880412.

21408877152 is a `hidden beast` number, since 21 + 408 + 8 + 77 + 152 = 666.

It is a super-2 number, since 2×21408877152² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21408877098 and 21408877107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9175378 + ... + 9177710.

It is an arithmetic number, because the mean of its divisors is an integer number (188703900).

Almost surely, 2^21408877152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21408877152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36231148800).

21408877152 is an abundant number, since it is smaller than the sum of its proper divisors (51053420448).

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

21408877152 is a wasteful number, since it uses less digits than its factorization.

21408877152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2427 (or 2413 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 45.

The spelling of 21408877152 in words is "twenty-one billion, four hundred eight million, eight hundred seventy-seven thousand, one hundred fifty-two".