662581 has 4 divisors (see below), whose sum is σ = 664812. Its totient is φ = 660352.

The previous prime is 662567. The next prime is 662591. The reversal of 662581 is 185266.

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 342225 + 320356 = 585^2 + 566^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-662581 is a prime.

It is a super-2 number, since 2×662581² = 878027163122, which contains 22 as substring.

It is a Duffinian number.

662581 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (662531) 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, 586 + ... + 1291.

It is an arithmetic number, because the mean of its divisors is an integer number (166203).

2⁶⁶²⁵⁸¹ is an apocalyptic number.

It is an amenable number.

662581 is a deficient number, since it is larger than the sum of its proper divisors (2231).

662581 is a wasteful number, since it uses less digits than its factorization.

662581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2230.

The product of its digits is 2880, while the sum is 28.

The square root of 662581 is about 813.9907861886. The cubic root of 662581 is about 87.1792227382.

The spelling of 662581 in words is "six hundred sixty-two thousand, five hundred eighty-one".