635868 has 36 divisors (see below), whose sum is σ = 1703520. Its totient is φ = 199296.

The previous prime is 635867. The next prime is 635879. The reversal of 635868 is 868536.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×635868² = 808656226848, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (635867) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 93 + ... + 1131.

It is an arithmetic number, because the mean of its divisors is an integer number (47320).

2⁶³⁵⁸⁶⁸ is an apocalyptic number.

635868 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 635868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (851760).

635868 is an abundant number, since it is smaller than the sum of its proper divisors (1067652).

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

635868 is a wasteful number, since it uses less digits than its factorization.

635868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066 (or 1061 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 635868 is about 797.4133181732. The cubic root of 635868 is about 85.9915261166.

The spelling of 635868 in words is "six hundred thirty-five thousand, eight hundred sixty-eight".