408688649 has 2 divisors, whose sum is σ = 408688650. Its totient is φ = 408688648.

The previous prime is 408688607. The next prime is 408688661. The reversal of 408688649 is 946886804.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 402403600 + 6285049 = 20060^2 + 2507^2 .

It is a cyclic number.

It is not a de Polignac number, because 408688649 - 2⁸ = 408688393 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 408688649.

It is not a weakly prime, because it can be changed into another prime (408688669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204344324 + 204344325.

It is an arithmetic number, because the mean of its divisors is an integer number (204344325).

Almost surely, 2^408688649 is an apocalyptic number.

It is an amenable number.

408688649 is a deficient number, since it is larger than the sum of its proper divisors (1).

408688649 is an equidigital number, since it uses as much as digits as its factorization.

408688649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2654208, while the sum is 53.

The square root of 408688649 is about 20216.0492925794. The cubic root of 408688649 is about 742.1030079335.

The spelling of 408688649 in words is "four hundred eight million, six hundred eighty-eight thousand, six hundred forty-nine".