920581 has 4 divisors (see below), whose sum is σ = 925452. Its totient is φ = 915712.

The previous prime is 920561. The next prime is 920609. The reversal of 920581 is 185029.

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

It can be written as a sum of positive squares in 2 ways, for example, as 893025 + 27556 = 945^2 + 166^2 .

It is a cyclic number.

It is not a de Polignac number, because 920581 - 2¹⁹ = 396293 is a prime.

It is a super-2 number, since 2×920581² = 1694938755122, which contains 22 as substring.

It is a Duffinian number.

920581 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (920561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2140 + ... + 2533.

It is an arithmetic number, because the mean of its divisors is an integer number (231363).

2⁹²⁰⁵⁸¹ is an apocalyptic number.

It is an amenable number.

920581 is a deficient number, since it is larger than the sum of its proper divisors (4871).

920581 is a wasteful number, since it uses less digits than its factorization.

920581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4870.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 920581 is about 959.4691240473. The cubic root of 920581 is about 97.2793520131.

The spelling of 920581 in words is "nine hundred twenty thousand, five hundred eighty-one".