508209661 has 6 divisors (see below), whose sum is σ = 513015230. Its totient is φ = 503448696.

The previous prime is 508209631. The next prime is 508209671. The reversal of 508209661 is 166902805.

It can be written as a sum of positive squares in only one way, i.e., 504900900 + 3308761 = 22470^2 + 1819^2 .

It is not a de Polignac number, because 508209661 - 2¹⁷ = 508078589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 508209661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (508209631) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10746 + ... + 33643.

Almost surely, 2^508209661 is an apocalyptic number.

It is an amenable number.

508209661 is a deficient number, since it is larger than the sum of its proper divisors (4805569).

508209661 is an equidigital number, since it uses as much as digits as its factorization.

508209661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44603 (or 44496 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 508209661 is about 22543.5059606974. The cubic root of 508209661 is about 798.0209734586.

The spelling of 508209661 in words is "five hundred eight million, two hundred nine thousand, six hundred sixty-one".