399618605 has 4 divisors (see below), whose sum is σ = 479542332. Its totient is φ = 319694880.

The previous prime is 399618587. The next prime is 399618647. The reversal of 399618605 is 506816993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 319301161 + 80317444 = 17869^2 + 8962^2 .

It is a de Polignac number, because none of the positive numbers 2^k-399618605 is a prime.

It is a Duffinian number.

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 399618605.

It is a congruent number.

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, 39961856 + ... + 39961865.

It is an arithmetic number, because the mean of its divisors is an integer number (119885583).

Almost surely, 2^399618605 is an apocalyptic number.

It is an amenable number.

399618605 is a deficient number, since it is larger than the sum of its proper divisors (79923727).

399618605 is an equidigital number, since it uses as much as digits as its factorization.

399618605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79923726.

The product of its (nonzero) digits is 349920, while the sum is 47.

The square root of 399618605 is about 19990.4628510698. The cubic root of 399618605 is about 736.5720467276.

The spelling of 399618605 in words is "three hundred ninety-nine million, six hundred eighteen thousand, six hundred five".