636980 has 12 divisors (see below), whose sum is σ = 1337700. Its totient is φ = 254784.

The previous prime is 636967. The next prime is 636983. The reversal of 636980 is 89636.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 274576 + 362404 = 524^2 + 602^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 636980.

It is not an unprimeable number, because it can be changed into a prime (636983) by changing a digit.

636980 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 3 ways as a sum of consecutive naturals, for example, 15905 + ... + 15944.

It is an arithmetic number, because the mean of its divisors is an integer number (111475).

2⁶³⁶⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

636980 is an abundant number, since it is smaller than the sum of its proper divisors (700720).

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

636980 is a wasteful number, since it uses less digits than its factorization.

636980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31858 (or 31856 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 636980 is about 798.1102680708. The cubic root of 636980 is about 86.0416239827.

The spelling of 636980 in words is "six hundred thirty-six thousand, nine hundred eighty".