636739 has 2 divisors, whose sum is σ = 636740. Its totient is φ = 636738.

The previous prime is 636731. The next prime is 636749. The reversal of 636739 is 937636.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 636739 - 2³ = 636731 is a prime.

It is not a weakly prime, because it can be changed into another prime (636731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318369 + 318370.

It is an arithmetic number, because the mean of its divisors is an integer number (318370).

2⁶³⁶⁷³⁹ is an apocalyptic number.

636739 is a deficient number, since it is larger than the sum of its proper divisors (1).

636739 is an equidigital number, since it uses as much as digits as its factorization.

636739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20412, while the sum is 34.

The square root of 636739 is about 797.9592721436. The cubic root of 636739 is about 86.0307713934.

The spelling of 636739 in words is "six hundred thirty-six thousand, seven hundred thirty-nine".