217922864 has 20 divisors (see below), whose sum is σ = 447062904. Its totient is φ = 102551808.

The previous prime is 217922833. The next prime is 217922869. The reversal of 217922864 is 468229712.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (217922869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400322 + ... + 400865.

Almost surely, 2^217922864 is an apocalyptic number.

It is an amenable number.

217922864 is an abundant number, since it is smaller than the sum of its proper divisors (229140040).

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

217922864 is a wasteful number, since it uses less digits than its factorization.

217922864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 801212 (or 801206 counting only the distinct ones).

The product of its digits is 96768, while the sum is 41.

The square root of 217922864 is about 14762.2106745568. The cubic root of 217922864 is about 601.7751723883.

The spelling of 217922864 in words is "two hundred seventeen million, nine hundred twenty-two thousand, eight hundred sixty-four".