503008661 has 2 divisors, whose sum is σ = 503008662. Its totient is φ = 503008660.

The previous prime is 503008609. The next prime is 503008663. The reversal of 503008661 is 166800305.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399600100 + 103408561 = 19990^2 + 10169^2 .

It is a cyclic number.

It is not a de Polignac number, because 503008661 - 2²⁶ = 435899797 is a prime.

It is a Sophie Germain prime.

Together with 503008663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (503008663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 251504330 + 251504331.

It is an arithmetic number, because the mean of its divisors is an integer number (251504331).

Almost surely, 2^503008661 is an apocalyptic number.

It is an amenable number.

503008661 is a deficient number, since it is larger than the sum of its proper divisors (1).

503008661 is an equidigital number, since it uses as much as digits as its factorization.

503008661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 503008661 is about 22427.8545786261. The cubic root of 503008661 is about 795.2893273350.

Adding to 503008661 its reverse (166800305), we get a palindrome (669808966).

The spelling of 503008661 in words is "five hundred three million, eight thousand, six hundred sixty-one".