636139 has 8 divisors (see below), whose sum is σ = 765440. Its totient is φ = 516456.

The previous prime is 636137. The next prime is 636149. The reversal of 636139 is 931636.

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

It is a cyclic number.

It is not a de Polignac number, because 636139 - 2¹ = 636137 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (636133) 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, 2259 + ... + 2524.

It is an arithmetic number, because the mean of its divisors is an integer number (95680).

2⁶³⁶¹³⁹ is an apocalyptic number.

636139 is a deficient number, since it is larger than the sum of its proper divisors (129301).

636139 is a wasteful number, since it uses less digits than its factorization.

636139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4809.

The product of its digits is 2916, while the sum is 28.

The square root of 636139 is about 797.5832244976. The cubic root of 636139 is about 86.0037405981.

It can be divided in two parts, 6361 and 39, that added together give a square (6400 = 80²).

The spelling of 636139 in words is "six hundred thirty-six thousand, one hundred thirty-nine".