638920368 has 30 divisors (see below), whose sum is σ = 1788090044. Its totient is φ = 212973408.

The previous prime is 638920361. The next prime is 638920369. The reversal of 638920368 is 863029836.

638920368 is a `hidden beast` number, since 6 + 389 + 203 + 68 = 666.

It is not an unprimeable number, because it can be changed into a prime (638920361) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2218330 + ... + 2218617.

Almost surely, 2^638920368 is an apocalyptic number.

It is an amenable number.

638920368 is an abundant number, since it is smaller than the sum of its proper divisors (1149169676).

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

638920368 is a wasteful number, since it uses less digits than its factorization.

638920368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4436961 (or 4436952 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 638920368 is about 25276.8741738372. The cubic root of 638920368 is about 861.2890206403.

The spelling of 638920368 in words is "six hundred thirty-eight million, nine hundred twenty thousand, three hundred sixty-eight".