638360066 has 4 divisors (see below), whose sum is σ = 957540102. Its totient is φ = 319180032.

The previous prime is 638360027. The next prime is 638360071. The reversal of 638360066 is 660063836.

It is a happy number.

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., 368448025 + 269912041 = 19195^2 + 16429^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159590015 + ... + 159590018.

Almost surely, 2^638360066 is an apocalyptic number.

638360066 is a deficient number, since it is larger than the sum of its proper divisors (319180036).

638360066 is a wasteful number, since it uses less digits than its factorization.

638360066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319180035.

The product of its (nonzero) digits is 93312, while the sum is 38.

The square root of 638360066 is about 25265.7884499970. The cubic root of 638360066 is about 861.0371775204.

The spelling of 638360066 in words is "six hundred thirty-eight million, three hundred sixty thousand, sixty-six".