636028638 has 32 divisors (see below), whose sum is σ = 1503912960. Its totient is φ = 175455840.

The previous prime is 636028619. The next prime is 636028669. The reversal of 636028638 is 836820636.

It is a super-2 number, since 2×636028638² = 809064856712270088, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 636028638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259878 + ... + 262313.

It is an arithmetic number, because the mean of its divisors is an integer number (46997280).

Almost surely, 2^636028638 is an apocalyptic number.

636028638 is an abundant number, since it is smaller than the sum of its proper divisors (867884322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

636028638 is a wasteful number, since it uses less digits than its factorization.

636028638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522232.

The product of its (nonzero) digits is 248832, while the sum is 42.

The square root of 636028638 is about 25219.6082047283. The cubic root of 636028638 is about 859.9876679321.

The spelling of 636028638 in words is "six hundred thirty-six million, twenty-eight thousand, six hundred thirty-eight".