408991816 has 16 divisors (see below), whose sum is σ = 772899840. Its totient is φ = 202885200.

The previous prime is 408991799. The next prime is 408991837. The reversal of 408991816 is 618199804.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200260 + ... + 202291.

It is an arithmetic number, because the mean of its divisors is an integer number (48306240).

Almost surely, 2^408991816 is an apocalyptic number.

It is an amenable number.

408991816 is a deficient number, since it is larger than the sum of its proper divisors (363908024).

408991816 is a wasteful number, since it uses less digits than its factorization.

408991816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402684 (or 402680 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 46.

The square root of 408991816 is about 20223.5460787667. The cubic root of 408991816 is about 742.2864609813.

The spelling of 408991816 in words is "four hundred eight million, nine hundred ninety-one thousand, eight hundred sixteen".