408316661 has 2 divisors, whose sum is σ = 408316662. Its totient is φ = 408316660.

The previous prime is 408316637. The next prime is 408316679. The reversal of 408316661 is 166613804.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 408282436 + 34225 = 20206^2 + 185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-408316661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (408316621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204158330 + 204158331.

It is an arithmetic number, because the mean of its divisors is an integer number (204158331).

Almost surely, 2^408316661 is an apocalyptic number.

It is an amenable number.

408316661 is a deficient number, since it is larger than the sum of its proper divisors (1).

408316661 is an equidigital number, since it uses as much as digits as its factorization.

408316661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 408316661 is about 20206.8468841628. The cubic root of 408316661 is about 741.8777857818.

The spelling of 408316661 in words is "four hundred eight million, three hundred sixteen thousand, six hundred sixty-one".