664535268 has 18 divisors (see below), whose sum is σ = 1679797574. Its totient is φ = 221511744.

The previous prime is 664535243. The next prime is 664535269. The reversal of 664535268 is 862535466.

It can be written as a sum of positive squares in only one way, i.e., 534164544 + 130370724 = 23112^2 + 11418^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (664535269) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9229621 + ... + 9229692.

Almost surely, 2^664535268 is an apocalyptic number.

It is an amenable number.

664535268 is an abundant number, since it is smaller than the sum of its proper divisors (1015262306).

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

664535268 is a wasteful number, since it uses less digits than its factorization.

664535268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18459323 (or 18459318 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The square root of 664535268 is about 25778.5815746328. The cubic root of 664535268 is about 872.6484967130.

The spelling of 664535268 in words is "six hundred sixty-four million, five hundred thirty-five thousand, two hundred sixty-eight".