639161 has 4 divisors (see below), whose sum is σ = 641424. Its totient is φ = 636900.

The previous prime is 639157. The next prime is 639167. The reversal of 639161 is 161936.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 639161 - 2² = 639157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 639161.

It is not an unprimeable number, because it can be changed into a prime (639167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 635 + ... + 1296.

It is an arithmetic number, because the mean of its divisors is an integer number (160356).

2⁶³⁹¹⁶¹ is an apocalyptic number.

It is an amenable number.

639161 is a deficient number, since it is larger than the sum of its proper divisors (2263).

639161 is a wasteful number, since it uses less digits than its factorization.

639161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2262.

The product of its digits is 972, while the sum is 26.

The square root of 639161 is about 799.4754530315. The cubic root of 639161 is about 86.1397134106.

The spelling of 639161 in words is "six hundred thirty-nine thousand, one hundred sixty-one".