639771171 has 8 divisors (see below), whose sum is σ = 918645840. Its totient is φ = 393705312.

The previous prime is 639771169. The next prime is 639771227. The reversal of 639771171 is 171177936.

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

It is not a de Polignac number, because 639771171 - 2¹ = 639771169 is a prime.

It is a super-2 number, since 2×639771171² = 818614302485422482, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (639771101) 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, 8202156 + ... + 8202233.

It is an arithmetic number, because the mean of its divisors is an integer number (114830730).

Almost surely, 2^639771171 is an apocalyptic number.

639771171 is a deficient number, since it is larger than the sum of its proper divisors (278874669).

639771171 is a wasteful number, since it uses less digits than its factorization.

639771171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16404405.

The product of its digits is 55566, while the sum is 42.

The square root of 639771171 is about 25293.6982467966. The cubic root of 639771171 is about 861.6711560328.

The spelling of 639771171 in words is "six hundred thirty-nine million, seven hundred seventy-one thousand, one hundred seventy-one".