21657676320 has 1152 divisors, whose sum is σ = 96371638272. Its totient is φ = 4478976000.

The previous prime is 21657676309. The next prime is 21657676421. The reversal of 21657676320 is 2367675612.

21657676320 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 7 + 6 + 7 + 632 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 143428245 + ... + 143428395.

It is an arithmetic number, because the mean of its divisors is an integer number (83655936).

Almost surely, 2^21657676320 is an apocalyptic number.

21657676320 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 21657676320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48185819136).

21657676320 is an abundant number, since it is smaller than the sum of its proper divisors (74713961952).

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

21657676320 is a wasteful number, since it uses less digits than its factorization.

21657676320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 45.

The spelling of 21657676320 in words is "twenty-one billion, six hundred fifty-seven million, six hundred seventy-six thousand, three hundred twenty".