636521 has 8 divisors (see below), whose sum is σ = 673920. Its totient is φ = 600208.

The previous prime is 636499. The next prime is 636533. The reversal of 636521 is 125636.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-636521 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (636541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1130 + ... + 1596.

It is an arithmetic number, because the mean of its divisors is an integer number (84240).

2⁶³⁶⁵²¹ is an apocalyptic number.

It is an amenable number.

636521 is a deficient number, since it is larger than the sum of its proper divisors (37399).

636521 is a wasteful number, since it uses less digits than its factorization.

636521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543.

The product of its digits is 1080, while the sum is 23.

The square root of 636521 is about 797.8226619995. The cubic root of 636521 is about 86.0209521692.

The spelling of 636521 in words is "six hundred thirty-six thousand, five hundred twenty-one".