8918639 has 2 divisors, whose sum is σ = 8918640. Its totient is φ = 8918638.

The previous prime is 8918621. The next prime is 8918653. The reversal of 8918639 is 9368198.

8918639 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8918639 is a prime.

It is a super-2 number, since 2×8918639² = 159084243224642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8918639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8918939) 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, 4459319 + 4459320.

It is an arithmetic number, because the mean of its divisors is an integer number (4459320).

Almost surely, 2^8918639 is an apocalyptic number.

8918639 is a deficient number, since it is larger than the sum of its proper divisors (1).

8918639 is an equidigital number, since it uses as much as digits as its factorization.

8918639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 44.

The square root of 8918639 is about 2986.4090476691. The cubic root of 8918639 is about 207.3796776660.

The spelling of 8918639 in words is "eight million, nine hundred eighteen thousand, six hundred thirty-nine".