216662564 has 6 divisors (see below), whose sum is σ = 379159494. Its totient is φ = 108331280.

The previous prime is 216662561. The next prime is 216662581. The reversal of 216662564 is 465266612.

It can be written as a sum of positive squares in only one way, i.e., 187416100 + 29246464 = 13690^2 + 5408^2 .

It is not an unprimeable number, because it can be changed into a prime (216662561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27082817 + ... + 27082824.

It is an arithmetic number, because the mean of its divisors is an integer number (63193249).

Almost surely, 2^216662564 is an apocalyptic number.

It is an amenable number.

216662564 is a deficient number, since it is larger than the sum of its proper divisors (162496930).

216662564 is a wasteful number, since it uses less digits than its factorization.

216662564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54165645 (or 54165643 counting only the distinct ones).

The product of its digits is 103680, while the sum is 38.

The square root of 216662564 is about 14719.4620825627. The cubic root of 216662564 is about 600.6128589785.

The spelling of 216662564 in words is "two hundred sixteen million, six hundred sixty-two thousand, five hundred sixty-four".