505730681 has 4 divisors (see below), whose sum is σ = 523169700. Its totient is φ = 488291664.

The previous prime is 505730677. The next prime is 505730707. The reversal of 505730681 is 186037505.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186037505 = 5 ⋅37207501.

It can be written as a sum of positive squares in 2 ways, for example, as 216560656 + 289170025 = 14716^2 + 17005^2 .

It is a cyclic number.

It is not a de Polignac number, because 505730681 - 2² = 505730677 is a prime.

It is a super-2 number, since 2×505730681² = 511527043409447522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (505730651) 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, 8719466 + ... + 8719523.

It is an arithmetic number, because the mean of its divisors is an integer number (130792425).

Almost surely, 2^505730681 is an apocalyptic number.

It is an amenable number.

505730681 is a deficient number, since it is larger than the sum of its proper divisors (17439019).

505730681 is a wasteful number, since it uses less digits than its factorization.

505730681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17439018.

The product of its (nonzero) digits is 25200, while the sum is 35.

The square root of 505730681 is about 22488.4566166734. The cubic root of 505730681 is about 796.7213107907.

The spelling of 505730681 in words is "five hundred five million, seven hundred thirty thousand, six hundred eighty-one".