21517702641640 has 64 divisors (see below), whose sum is σ = 49209388090560. Its totient is φ = 8466202652160.

The previous prime is 21517702641559. The next prime is 21517702641671. The reversal of 21517702641640 is 4614620771512.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4047301 + ... + 7708180.

It is an arithmetic number, because the mean of its divisors is an integer number (768896688915).

Almost surely, 2^{21517702641640} is an apocalyptic number.

21517702641640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21517702641640 is an abundant number, since it is smaller than the sum of its proper divisors (27691685448920).

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

21517702641640 is a wasteful number, since it uses less digits than its factorization.

21517702641640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11756242 (or 11756238 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 46.

The spelling of 21517702641640 in words is "twenty-one trillion, five hundred seventeen billion, seven hundred two million, six hundred forty-one thousand, six hundred forty".