636309139 has 2 divisors, whose sum is σ = 636309140. Its totient is φ = 636309138.

The previous prime is 636309071. The next prime is 636309143. The reversal of 636309139 is 931903636.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 636309139 - 2¹⁵ = 636276371 is a prime.

It is not a weakly prime, because it can be changed into another prime (636309169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318154569 + 318154570.

It is an arithmetic number, because the mean of its divisors is an integer number (318154570).

Almost surely, 2^636309139 is an apocalyptic number.

636309139 is a deficient number, since it is larger than the sum of its proper divisors (1).

636309139 is an equidigital number, since it uses as much as digits as its factorization.

636309139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 78732, while the sum is 40.

The square root of 636309139 is about 25225.1687605851. The cubic root of 636309139 is about 860.1140731142.

The spelling of 636309139 in words is "six hundred thirty-six million, three hundred nine thousand, one hundred thirty-nine".