636660 has 72 divisors (see below), whose sum is σ = 2018016. Its totient is φ = 168480.

The previous prime is 636653. The next prime is 636673. The reversal of 636660 is 66636.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4795 + ... + 4925.

It is an arithmetic number, because the mean of its divisors is an integer number (28028).

2⁶³⁶⁶⁶⁰ is an apocalyptic number.

636660 is a gapful number since it is divisible by the number (60) 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 636660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1009008).

636660 is an abundant number, since it is smaller than the sum of its proper divisors (1381356).

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

636660 is a wasteful number, since it uses less digits than its factorization.

636660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 636660 is about 797.9097693349. The cubic root of 636660 is about 86.0272133096.

It can be divided in two parts, 636 and 660, that added together give a 4-th power (1296 = 6⁴).

The spelling of 636660 in words is "six hundred thirty-six thousand, six hundred sixty".