506005781 has 4 divisors (see below), whose sum is σ = 508123200. Its totient is φ = 503888364.

The previous prime is 506005763. The next prime is 506005789. The reversal of 506005781 is 187500605.

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 not a de Polignac number, because 506005781 - 2¹⁰ = 506004757 is a prime.

It is a super-2 number, since 2×506005781² = 512083700810839922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (506005789) 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, 1058351 + ... + 1058828.

It is an arithmetic number, because the mean of its divisors is an integer number (127030800).

Almost surely, 2^506005781 is an apocalyptic number.

It is an amenable number.

506005781 is a deficient number, since it is larger than the sum of its proper divisors (2117419).

506005781 is a wasteful number, since it uses less digits than its factorization.

506005781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2117418.

The product of its (nonzero) digits is 8400, while the sum is 32.

The square root of 506005781 is about 22494.5722564356. The cubic root of 506005781 is about 796.8657475507.

The spelling of 506005781 in words is "five hundred six million, five thousand, seven hundred eighty-one".