636690 has 32 divisors (see below), whose sum is σ = 1609920. Its totient is φ = 160704.

The previous prime is 636673. The next prime is 636697. The reversal of 636690 is 96636.

636690 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×636690² = 810748312200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (636697) by changing a digit.

636690 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12 + ... + 1128.

It is an arithmetic number, because the mean of its divisors is an integer number (50310).

2⁶³⁶⁶⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 636690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (804960).

636690 is an abundant number, since it is smaller than the sum of its proper divisors (973230).

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

636690 is a wasteful number, since it uses less digits than its factorization.

636690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1146.

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 636690 is about 797.9285682315. The cubic root of 636690 is about 86.0285645153.

It can be divided in two parts, 636 and 690, that added together give a triangular number (1326 = T₅₁).

The spelling of 636690 in words is "six hundred thirty-six thousand, six hundred ninety".