21646117390320 has 960 divisors, whose sum is σ = 79001433298944. Its totient is φ = 5291681218560.

The previous prime is 21646117390297. The next prime is 21646117390333. The reversal of 21646117390320 is 2309371164612.

21646117390320 is a `hidden beast` number, since 2 + 1 + 6 + 4 + 611 + 7 + 3 + 9 + 0 + 3 + 20 = 666.

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

It is a congruent number.

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, 38447810359 + ... + 38447810921.

Almost surely, 2^{21646117390320} is an apocalyptic number.

21646117390320 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 21646117390320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39500716649472).

21646117390320 is an abundant number, since it is smaller than the sum of its proper divisors (57355315908624).

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

21646117390320 is a wasteful number, since it uses less digits than its factorization.

21646117390320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1110 (or 1101 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The spelling of 21646117390320 in words is "twenty-one trillion, six hundred forty-six billion, one hundred seventeen million, three hundred ninety thousand, three hundred twenty".