664428132 has 18 divisors (see below), whose sum is σ = 1679526758. Its totient is φ = 221476032.

The previous prime is 664428109. The next prime is 664428133. The reversal of 664428132 is 231824466.

664428132 is a `hidden beast` number, since 6 + 644 + 2 + 8 + 1 + 3 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 502477056 + 161951076 = 22416^2 + 12726^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18456337 = 664428132 / (6 + 6 + 4 + 4 + 2 + 8 + 1 + 3 + 2).

It is not an unprimeable number, because it can be changed into a prime (664428133) 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, 9228133 + ... + 9228204.

Almost surely, 2^664428132 is an apocalyptic number.

It is an amenable number.

664428132 is an abundant number, since it is smaller than the sum of its proper divisors (1015098626).

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

664428132 is a wasteful number, since it uses less digits than its factorization.

664428132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18456347 (or 18456342 counting only the distinct ones).

The product of its digits is 55296, while the sum is 36.

The square root of 664428132 is about 25776.5034867028. The cubic root of 664428132 is about 872.6015982269.

The spelling of 664428132 in words is "six hundred sixty-four million, four hundred twenty-eight thousand, one hundred thirty-two".