399444993 has 16 divisors (see below), whose sum is σ = 592088640. Its totient is φ = 266153472.

The previous prime is 399444967. The next prime is 399445003.

399444993 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 399444993 - 2⁹ = 399444481 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (399444293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77505 + ... + 82497.

It is an arithmetic number, because the mean of its divisors is an integer number (37005540).

Almost surely, 2^399444993 is an apocalyptic number.

It is an amenable number.

399444993 is a deficient number, since it is larger than the sum of its proper divisors (192643647).

399444993 is a wasteful number, since it uses less digits than its factorization.

399444993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7965 (or 7959 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 54.

The square root of 399444993 is about 19986.1200086460. The cubic root of 399444993 is about 736.4653647834.

The spelling of 399444993 in words is "three hundred ninety-nine million, four hundred forty-four thousand, nine hundred ninety-three".