8638139 has 2 divisors, whose sum is σ = 8638140. Its totient is φ = 8638138.

The previous prime is 8638121. The next prime is 8638151. The reversal of 8638139 is 9318368.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8638139 is a prime.

It is equal to p₅₇₉₈₃₆ and since 8638139 and 579836 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (8638199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4319069 + 4319070.

It is an arithmetic number, because the mean of its divisors is an integer number (4319070).

Almost surely, 2^8638139 is an apocalyptic number.

8638139 is a deficient number, since it is larger than the sum of its proper divisors (1).

8638139 is an equidigital number, since it uses as much as digits as its factorization.

8638139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 38.

The square root of 8638139 is about 2939.0711117630. The cubic root of 8638139 is about 205.1823798339.

The spelling of 8638139 in words is "eight million, six hundred thirty-eight thousand, one hundred thirty-nine".