664387236 has 18 divisors (see below), whose sum is σ = 1679423382. Its totient is φ = 221462400.

The previous prime is 664387201. The next prime is 664387237. The reversal of 664387236 is 632783466.

It can be written as a sum of positive squares in only one way, i.e., 357436836 + 306950400 = 18906^2 + 17520^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 664387191 and 664387200.

It is not an unprimeable number, because it can be changed into a prime (664387237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9227565 + ... + 9227636.

It is an arithmetic number, because the mean of its divisors is an integer number (93301299).

Almost surely, 2^664387236 is an apocalyptic number.

It is an amenable number.

664387236 is an abundant number, since it is smaller than the sum of its proper divisors (1015036146).

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

664387236 is a wasteful number, since it uses less digits than its factorization.

664387236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18455211 (or 18455206 counting only the distinct ones).

The product of its digits is 870912, while the sum is 45.

The square root of 664387236 is about 25775.7101939015. The cubic root of 664387236 is about 872.5836947871.

The spelling of 664387236 in words is "six hundred sixty-four million, three hundred eighty-seven thousand, two hundred thirty-six".