635540 has 24 divisors (see below), whose sum is σ = 1367520. Its totient is φ = 247968.

The previous prime is 635533. The next prime is 635563. The reversal of 635540 is 45536.

It is a super-2 number, since 2×635540² = 807822183200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 491 + ... + 1229.

It is an arithmetic number, because the mean of its divisors is an integer number (56980).

2⁶³⁵⁵⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 635540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (683760).

635540 is an abundant number, since it is smaller than the sum of its proper divisors (731980).

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

635540 is a wasteful number, since it uses less digits than its factorization.

635540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791 (or 789 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 635540 is about 797.2076266569. The cubic root of 635540 is about 85.9767378945.

The spelling of 635540 in words is "six hundred thirty-five thousand, five hundred forty".