636605687 has 2 divisors, whose sum is σ = 636605688. Its totient is φ = 636605686.

The previous prime is 636605633. The next prime is 636605713. The reversal of 636605687 is 786506636.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 636605687 - 2²⁴ = 619828471 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 (36605687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318302843 + 318302844.

It is an arithmetic number, because the mean of its divisors is an integer number (318302844).

Almost surely, 2^636605687 is an apocalyptic number.

636605687 is a deficient number, since it is larger than the sum of its proper divisors (1).

636605687 is an equidigital number, since it uses as much as digits as its factorization.

636605687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 47.

The square root of 636605687 is about 25231.0460940485. The cubic root of 636605687 is about 860.2476693381.

The spelling of 636605687 in words is "six hundred thirty-six million, six hundred five thousand, six hundred eighty-seven".