505681 has 4 divisors (see below), whose sum is σ = 551664. Its totient is φ = 459700.

The previous prime is 505669. The next prime is 505691. The reversal of 505681 is 186505.

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 a de Polignac number, because none of the positive numbers 2^k-505681 is a prime.

It is a super-2 number, since 2×505681² = 511426547522, which contains 22 as substring.

It is a Duffinian number.

505681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (505601) 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, 22975 + ... + 22996.

It is an arithmetic number, because the mean of its divisors is an integer number (137916).

2⁵⁰⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

505681 is a deficient number, since it is larger than the sum of its proper divisors (45983).

505681 is a wasteful number, since it uses less digits than its factorization.

505681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45982.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 505681 is about 711.1125086792. The cubic root of 505681 is about 79.6695221010.

The spelling of 505681 in words is "five hundred five thousand, six hundred eighty-one".