638131173 has 16 divisors (see below), whose sum is σ = 881197056. Its totient is φ = 410498480.

The previous prime is 638131163. The next prime is 638131181. The reversal of 638131173 is 371131836.

It is a cyclic number.

It is not a de Polignac number, because 638131173 - 2¹⁰ = 638130149 is a prime.

It is a super-2 number, since 2×638131173² = 814422787908711858, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638131133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21861 + ... + 41882.

It is an arithmetic number, because the mean of its divisors is an integer number (55074816).

Almost surely, 2^638131173 is an apocalyptic number.

It is an amenable number.

638131173 is a deficient number, since it is larger than the sum of its proper divisors (243065883).

638131173 is a wasteful number, since it uses less digits than its factorization.

638131173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63864.

The product of its digits is 9072, while the sum is 33.

The square root of 638131173 is about 25261.2583415791. The cubic root of 638131173 is about 860.9342528787.

The spelling of 638131173 in words is "six hundred thirty-eight million, one hundred thirty-one thousand, one hundred seventy-three".