217668972 has 18 divisors (see below), whose sum is σ = 508013548. Its totient is φ = 72539288.

The previous prime is 217668961. The next prime is 217668989. The reversal of 217668972 is 279866712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 48979 + ... + 53237.

Almost surely, 2^217668972 is an apocalyptic number.

It is an amenable number.

217668972 is an abundant number, since it is smaller than the sum of its proper divisors (290344576).

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

217668972 is an frugal number, since it uses more digits than its factorization.

217668972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8525 (or 4264 counting only the distinct ones).

The product of its digits is 508032, while the sum is 48.

The square root of 217668972 is about 14753.6087788717. The cubic root of 217668972 is about 601.5413812931.

Multiplying 217668972 by its sum of digits (48), we get a square (10448110656 = 102216²).

The spelling of 217668972 in words is "two hundred seventeen million, six hundred sixty-eight thousand, nine hundred seventy-two".