985708639 has 2 divisors, whose sum is σ = 985708640. Its totient is φ = 985708638.

The previous prime is 985708589. The next prime is 985708663. The reversal of 985708639 is 936807589.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 985708639 - 2²³ = 977320031 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 985708639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (985708439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 492854319 + 492854320.

It is an arithmetic number, because the mean of its divisors is an integer number (492854320).

Almost surely, 2^985708639 is an apocalyptic number.

985708639 is a deficient number, since it is larger than the sum of its proper divisors (1).

985708639 is an equidigital number, since it uses as much as digits as its factorization.

985708639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3265920, while the sum is 55.

The square root of 985708639 is about 31395.9971811694. The cubic root of 985708639 is about 995.2133374189.

The spelling of 985708639 in words is "nine hundred eighty-five million, seven hundred eight thousand, six hundred thirty-nine".