635840 has 28 divisors (see below), whose sum is σ = 1514856. Its totient is φ = 254208.

The previous prime is 635837. The next prime is 635849. The reversal of 635840 is 48536.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (635849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 674 + ... + 1313.

It is an arithmetic number, because the mean of its divisors is an integer number (54102).

2⁶³⁵⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

635840 is an abundant number, since it is smaller than the sum of its proper divisors (879016).

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

635840 is a wasteful number, since it uses less digits than its factorization.

635840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2004 (or 1994 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 635840 is about 797.3957612127. The cubic root of 635840 is about 85.9902639059.

The spelling of 635840 in words is "six hundred thirty-five thousand, eight hundred forty".