636445 has 4 divisors (see below), whose sum is σ = 763740. Its totient is φ = 509152.

The previous prime is 636421. The next prime is 636469. The reversal of 636445 is 544636.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (636421) and next prime (636469).

It can be written as a sum of positive squares in 2 ways, for example, as 143641 + 492804 = 379^2 + 702^2 .

It is a cyclic number.

It is not a de Polignac number, because 636445 - 2¹¹ = 634397 is a prime.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 63640 + ... + 63649.

It is an arithmetic number, because the mean of its divisors is an integer number (190935).

2⁶³⁶⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

636445 is a deficient number, since it is larger than the sum of its proper divisors (127295).

636445 is a wasteful number, since it uses less digits than its factorization.

636445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127294.

The product of its digits is 8640, while the sum is 28.

The square root of 636445 is about 797.7750309454. The cubic root of 636445 is about 86.0175284264.

Subtracting from 636445 its reverse (544636), we obtain a square (91809 = 303²).

It can be divided in two parts, 636 and 445, that added together give a triangular number (1081 = T₄₆).

The spelling of 636445 in words is "six hundred thirty-six thousand, four hundred forty-five".