634985639 has 2 divisors, whose sum is σ = 634985640. Its totient is φ = 634985638.

The previous prime is 634985623. The next prime is 634985669. The reversal of 634985639 is 936589436.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 634985639 - 2⁴ = 634985623 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (634985669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317492819 + 317492820.

It is an arithmetic number, because the mean of its divisors is an integer number (317492820).

Almost surely, 2^634985639 is an apocalyptic number.

634985639 is a deficient number, since it is larger than the sum of its proper divisors (1).

634985639 is an equidigital number, since it uses as much as digits as its factorization.

634985639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4199040, while the sum is 53.

The square root of 634985639 is about 25198.9213856466. The cubic root of 634985639 is about 859.5173237937.

The spelling of 634985639 in words is "six hundred thirty-four million, nine hundred eighty-five thousand, six hundred thirty-nine".