520281661 has 4 divisors (see below), whose sum is σ = 521676892. Its totient is φ = 518886432.

The previous prime is 520281659. The next prime is 520281667. The reversal of 520281661 is 166182025.

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 416364025 + 103917636 = 20405^2 + 10194^2 .

It is a cyclic number.

It is not a de Polignac number, because 520281661 - 2¹ = 520281659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520281667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 697056 + ... + 697801.

It is an arithmetic number, because the mean of its divisors is an integer number (130419223).

Almost surely, 2^520281661 is an apocalyptic number.

It is an amenable number.

520281661 is a deficient number, since it is larger than the sum of its proper divisors (1395231).

520281661 is a wasteful number, since it uses less digits than its factorization.

520281661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1395230.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 520281661 is about 22809.6834918856. The cubic root of 520281661 is about 804.2903154649.

The spelling of 520281661 in words is "five hundred twenty million, two hundred eighty-one thousand, six hundred sixty-one".