636491647 has 16 divisors (see below), whose sum is σ = 700545024. Its totient is φ = 573496000.

The previous prime is 636491591. The next prime is 636491651. The reversal of 636491647 is 746194636.

It is a happy number.

It is not a de Polignac number, because 636491647 - 2⁷ = 636491519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 636491597 and 636491606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636491677) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1031283 + ... + 1031899.

It is an arithmetic number, because the mean of its divisors is an integer number (43784064).

Almost surely, 2^636491647 is an apocalyptic number.

636491647 is a deficient number, since it is larger than the sum of its proper divisors (64053377).

636491647 is a wasteful number, since it uses less digits than its factorization.

636491647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1310.

The product of its digits is 653184, while the sum is 46.

The square root of 636491647 is about 25228.7860786047. The cubic root of 636491647 is about 860.1962987096.

The spelling of 636491647 in words is "six hundred thirty-six million, four hundred ninety-one thousand, six hundred forty-seven".