217490660 has 12 divisors (see below), whose sum is σ = 456730428. Its totient is φ = 86996256.

The previous prime is 217490597. The next prime is 217490683. The reversal of 217490660 is 66094712.

It can be written as a sum of positive squares in 2 ways, for example, as 121176064 + 96314596 = 11008^2 + 9814^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 217490660.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5437247 + ... + 5437286.

It is an arithmetic number, because the mean of its divisors is an integer number (38060869).

Almost surely, 2^217490660 is an apocalyptic number.

217490660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217490660 is an abundant number, since it is smaller than the sum of its proper divisors (239239768).

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

217490660 is a wasteful number, since it uses less digits than its factorization.

217490660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10874542 (or 10874540 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 217490660 is about 14747.5645446969. The cubic root of 217490660 is about 601.3770777509.

The spelling of 217490660 in words is "two hundred seventeen million, four hundred ninety thousand, six hundred sixty".