221585668 has 6 divisors (see below), whose sum is σ = 387774926. Its totient is φ = 110792832.

The previous prime is 221585621. The next prime is 221585669. The reversal of 221585668 is 866585122.

It can be written as a sum of positive squares in only one way, i.e., 178970884 + 42614784 = 13378^2 + 6528^2 .

It is not an unprimeable number, because it can be changed into a prime (221585669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27698205 + ... + 27698212.

Almost surely, 2^221585668 is an apocalyptic number.

It is an amenable number.

221585668 is a deficient number, since it is larger than the sum of its proper divisors (166189258).

221585668 is a wasteful number, since it uses less digits than its factorization.

221585668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55396421 (or 55396419 counting only the distinct ones).

The product of its digits is 230400, while the sum is 43.

The square root of 221585668 is about 14885.7538606548. The cubic root of 221585668 is about 605.1279632794.

The spelling of 221585668 in words is "two hundred twenty-one million, five hundred eighty-five thousand, six hundred sixty-eight".