664742388 has 24 divisors (see below), whose sum is σ = 1564795008. Its totient is φ = 219619456.

The previous prime is 664742387. The next prime is 664742401. The reversal of 664742388 is 883247466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664742387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 243756 + ... + 246467.

It is an arithmetic number, because the mean of its divisors is an integer number (65199792).

Almost surely, 2^664742388 is an apocalyptic number.

It is an amenable number.

664742388 is an abundant number, since it is smaller than the sum of its proper divisors (900052620).

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

664742388 is a wasteful number, since it uses less digits than its factorization.

664742388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490343 (or 490341 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 48.

The square root of 664742388 is about 25782.5985501850. The cubic root of 664742388 is about 872.7391486271.

The spelling of 664742388 in words is "six hundred sixty-four million, seven hundred forty-two thousand, three hundred eighty-eight".