399866843 has 4 divisors (see below), whose sum is σ = 423388440. Its totient is φ = 376345248.

The previous prime is 399866839. The next prime is 399866869. The reversal of 399866843 is 348668993.

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

It is a cyclic number.

It is not a de Polignac number, because 399866843 - 2² = 399866839 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399866813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11760773 + ... + 11760806.

It is an arithmetic number, because the mean of its divisors is an integer number (105847110).

Almost surely, 2^399866843 is an apocalyptic number.

399866843 is a deficient number, since it is larger than the sum of its proper divisors (23521597).

399866843 is a wasteful number, since it uses less digits than its factorization.

399866843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23521596.

The product of its digits is 6718464, while the sum is 56.

The square root of 399866843 is about 19996.6707979103. The cubic root of 399866843 is about 736.7245315570.

The spelling of 399866843 in words is "three hundred ninety-nine million, eight hundred sixty-six thousand, eight hundred forty-three".