21643922160 has 240 divisors, whose sum is σ = 83262069696. Its totient is φ = 4935831552.

The previous prime is 21643922141. The next prime is 21643922171. The reversal of 21643922160 is 6122934612.

It is a happy number.

21643922160 is a `hidden beast` number, since 2 + 1 + 6 + 439 + 2 + 216 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2298582 + ... + 2307978.

Almost surely, 2^21643922160 is an apocalyptic number.

21643922160 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 21643922160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41631034848).

21643922160 is an abundant number, since it is smaller than the sum of its proper divisors (61618147536).

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

21643922160 is a wasteful number, since it uses less digits than its factorization.

21643922160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9880 (or 9871 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The spelling of 21643922160 in words is "twenty-one billion, six hundred forty-three million, nine hundred twenty-two thousand, one hundred sixty".