664742306 has 4 divisors (see below), whose sum is σ = 997113462. Its totient is φ = 332371152.

The previous prime is 664742249. The next prime is 664742359. The reversal of 664742306 is 603247466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 574321225 + 90421081 = 23965^2 + 9509^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 664742306.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166185575 + ... + 166185578.

Almost surely, 2^664742306 is an apocalyptic number.

664742306 is a deficient number, since it is larger than the sum of its proper divisors (332371156).

664742306 is a wasteful number, since it uses less digits than its factorization.

664742306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332371155.

The product of its (nonzero) digits is 145152, while the sum is 38.

The square root of 664742306 is about 25782.5969599651. The cubic root of 664742306 is about 872.7391127412.

The spelling of 664742306 in words is "six hundred sixty-four million, seven hundred forty-two thousand, three hundred six".