638983171 has 4 divisors (see below), whose sum is σ = 666765072. Its totient is φ = 611201272.

The previous prime is 638983141. The next prime is 638983183. The reversal of 638983171 is 171389836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638983171 - 2¹⁷ = 638852099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638983141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13890916 + ... + 13890961.

It is an arithmetic number, because the mean of its divisors is an integer number (166691268).

Almost surely, 2^638983171 is an apocalyptic number.

638983171 is a deficient number, since it is larger than the sum of its proper divisors (27781901).

638983171 is a wasteful number, since it uses less digits than its factorization.

638983171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27781900.

The product of its digits is 217728, while the sum is 46.

The square root of 638983171 is about 25278.1164448619. The cubic root of 638983171 is about 861.3172399954.

The spelling of 638983171 in words is "six hundred thirty-eight million, nine hundred eighty-three thousand, one hundred seventy-one".