636281 has 4 divisors (see below), whose sum is σ = 639312. Its totient is φ = 633252.

The previous prime is 636277. The next prime is 636283. The reversal of 636281 is 182636.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 636281 - 2² = 636277 is a prime.

It is a super-2 number, since 2×636281² = 809707021922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 636281.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 636281.

It is not an unprimeable number, because it can be changed into a prime (636283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1175 + ... + 1628.

It is an arithmetic number, because the mean of its divisors is an integer number (159828).

2⁶³⁶²⁸¹ is an apocalyptic number.

It is an amenable number.

636281 is a deficient number, since it is larger than the sum of its proper divisors (3031).

636281 is a wasteful number, since it uses less digits than its factorization.

636281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3030.

The product of its digits is 1728, while the sum is 26.

The square root of 636281 is about 797.6722384539. The cubic root of 636281 is about 86.0101394211.

The spelling of 636281 in words is "six hundred thirty-six thousand, two hundred eighty-one".