636890 has 8 divisors (see below), whose sum is σ = 1146420. Its totient is φ = 254752.

The previous prime is 636877. The next prime is 636917. The reversal of 636890 is 98636.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 635209 + 1681 = 797^2 + 41^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31835 + ... + 31854.

2⁶³⁶⁸⁹⁰ is an apocalyptic number.

636890 is a deficient number, since it is larger than the sum of its proper divisors (509530).

636890 is a wasteful number, since it uses less digits than its factorization.

636890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63696.

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

The square root of 636890 is about 798.0538828926. The cubic root of 636890 is about 86.0375714688.

The spelling of 636890 in words is "six hundred thirty-six thousand, eight hundred ninety".