638005057 has 4 divisors (see below), whose sum is σ = 638253700. Its totient is φ = 637756416.

The previous prime is 638005051. The next prime is 638005111. The reversal of 638005057 is 750500836.

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 2 ways, for example, as 538982656 + 99022401 = 23216^2 + 9951^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638005057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638005051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120432 + ... + 125617.

It is an arithmetic number, because the mean of its divisors is an integer number (159563425).

Almost surely, 2^638005057 is an apocalyptic number.

It is an amenable number.

638005057 is a deficient number, since it is larger than the sum of its proper divisors (248643).

638005057 is a wasteful number, since it uses less digits than its factorization.

638005057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248642.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 638005057 is about 25258.7619847054. The cubic root of 638005057 is about 860.8775327024.

The spelling of 638005057 in words is "six hundred thirty-eight million, five thousand, fifty-seven".