636740 has 48 divisors (see below), whose sum is σ = 1505280. Its totient is φ = 224640.

The previous prime is 636739. The next prime is 636749. The reversal of 636740 is 47636.

636740 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636749) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8021 + ... + 8099.

It is an arithmetic number, because the mean of its divisors is an integer number (31360).

2⁶³⁶⁷⁴⁰ 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 636740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (752640).

636740 is an abundant number, since it is smaller than the sum of its proper divisors (868540).

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

636740 is a wasteful number, since it uses less digits than its factorization.

636740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 636740 is about 797.9598987418. The cubic root of 636740 is about 86.0308164305.

The spelling of 636740 in words is "six hundred thirty-six thousand, seven hundred forty".