638211057 has 8 divisors (see below), whose sum is σ = 928307040. Its totient is φ = 386794560.

The previous prime is 638211019. The next prime is 638211089. The reversal of 638211057 is 750112836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638211057 - 2⁷ = 638210929 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 19339729 = 638211057 / (6 + 3 + 8 + 2 + 1 + 1 + 0 + 5 + 7).

It is not an unprimeable number, because it can be changed into a prime (638211017) 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, 9669832 + ... + 9669897.

It is an arithmetic number, because the mean of its divisors is an integer number (116038380).

Almost surely, 2^638211057 is an apocalyptic number.

It is an amenable number.

638211057 is a deficient number, since it is larger than the sum of its proper divisors (290095983).

638211057 is a wasteful number, since it uses less digits than its factorization.

638211057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19339743.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 638211057 is about 25262.8394484864. The cubic root of 638211057 is about 860.9701765284.

The spelling of 638211057 in words is "six hundred thirty-eight million, two hundred eleven thousand, fifty-seven".