221994664 has 32 divisors (see below), whose sum is σ = 430597440. Its totient is φ = 107222400.

The previous prime is 221994659. The next prime is 221994697. The reversal of 221994664 is 466499122.

It is a self number, because there is not a number n which added to its sum of digits gives 221994664.

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, 30499 + ... + 37069.

It is an arithmetic number, because the mean of its divisors is an integer number (13456170).

Almost surely, 2^221994664 is an apocalyptic number.

It is an amenable number.

221994664 is a deficient number, since it is larger than the sum of its proper divisors (208602776).

221994664 is a wasteful number, since it uses less digits than its factorization.

221994664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6721 (or 6717 counting only the distinct ones).

The product of its digits is 186624, while the sum is 43.

The square root of 221994664 is about 14899.4853602398. The cubic root of 221994664 is about 605.5000432998.

The spelling of 221994664 in words is "two hundred twenty-one million, nine hundred ninety-four thousand, six hundred sixty-four".