636428631 has 4 divisors (see below), whose sum is σ = 848571512. Its totient is φ = 424285752.

The previous prime is 636428627. The next prime is 636428633. The reversal of 636428631 is 136824636.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 636428631 - 2² = 636428627 is a prime.

It is a super-3 number, since 3×636428631³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 636428631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636428633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106071436 + ... + 106071441.

It is an arithmetic number, because the mean of its divisors is an integer number (212142878).

Almost surely, 2^636428631 is an apocalyptic number.

636428631 is a deficient number, since it is larger than the sum of its proper divisors (212142881).

636428631 is a wasteful number, since it uses less digits than its factorization.

636428631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212142880.

The product of its digits is 124416, while the sum is 39.

The square root of 636428631 is about 25227.5371568451. The cubic root of 636428631 is about 860.1679097961.

The spelling of 636428631 in words is "six hundred thirty-six million, four hundred twenty-eight thousand, six hundred thirty-one".