217040657660 has 24 divisors (see below), whose sum is σ = 455950219200. Its totient is φ = 86784865344.

The previous prime is 217040657609. The next prime is 217040657681. The reversal of 217040657660 is 66756040712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1905635 + ... + 2016314.

It is an arithmetic number, because the mean of its divisors is an integer number (18997925800).

Almost surely, 2^217040657660 is an apocalyptic number.

217040657660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217040657660 is an abundant number, since it is smaller than the sum of its proper divisors (238909561540).

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

217040657660 is a wasteful number, since it uses less digits than its factorization.

217040657660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3924725 (or 3924723 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 44.

The spelling of 217040657660 in words is "two hundred seventeen billion, forty million, six hundred fifty-seven thousand, six hundred sixty".