217689708740 has 24 divisors (see below), whose sum is σ = 522455301312. Its totient is φ = 74636471520.

The previous prime is 217689708737. The next prime is 217689708799. The reversal of 217689708740 is 47807986712.

It is a self number, because there is not a number n which added to its sum of digits gives 217689708740.

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, 777463106 + ... + 777463385.

It is an arithmetic number, because the mean of its divisors is an integer number (21768970888).

Almost surely, 2^217689708740 is an apocalyptic number.

217689708740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217689708740 is an abundant number, since it is smaller than the sum of its proper divisors (304765592572).

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

217689708740 is a wasteful number, since it uses less digits than its factorization.

217689708740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1554926507 (or 1554926505 counting only the distinct ones).

The product of its (nonzero) digits is 9483264, while the sum is 59.

The spelling of 217689708740 in words is "two hundred seventeen billion, six hundred eighty-nine million, seven hundred eight thousand, seven hundred forty".