639542163 has 32 divisors (see below), whose sum is σ = 969131520. Its totient is φ = 372176640.

The previous prime is 639542143. The next prime is 639542173. The reversal of 639542163 is 361245936.

639542163 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 639542163 - 2¹⁴ = 639525779 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (639542143) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 75828 + ... + 83838.

It is an arithmetic number, because the mean of its divisors is an integer number (30285360).

Almost surely, 2^639542163 is an apocalyptic number.

639542163 is a deficient number, since it is larger than the sum of its proper divisors (329589357).

639542163 is a wasteful number, since it uses less digits than its factorization.

639542163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8139.

The product of its digits is 116640, while the sum is 39.

The square root of 639542163 is about 25289.1708642257. The cubic root of 639542163 is about 861.5683311757.

The spelling of 639542163 in words is "six hundred thirty-nine million, five hundred forty-two thousand, one hundred sixty-three".