664401384 has 24 divisors (see below), whose sum is σ = 1799420610. Its totient is φ = 221467104.

The previous prime is 664401379. The next prime is 664401407. The reversal of 664401384 is 483104466.

664401384 is a `hidden beast` number, since 6 + 644 + 0 + 1 + 3 + 8 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 507600900 + 156800484 = 22530^2 + 12522^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×664401384² = 882858398122230912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4613827 + ... + 4613970.

Almost surely, 2^664401384 is an apocalyptic number.

It is an amenable number.

664401384 is an abundant number, since it is smaller than the sum of its proper divisors (1135019226).

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

664401384 is a wasteful number, since it uses less digits than its factorization.

664401384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9227809 (or 9227802 counting only the distinct ones).

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

The square root of 664401384 is about 25775.9846368669. The cubic root of 664401384 is about 872.5898885778.

The spelling of 664401384 in words is "six hundred sixty-four million, four hundred one thousand, three hundred eighty-four".