399303993 has 20 divisors (see below), whose sum is σ = 585706640. Its totient is φ = 241975800.

The previous prime is 399303967. The next prime is 399304001.

399303993 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 399303993 - 2¹² = 399299897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399303913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 39378 + ... + 48468.

It is an arithmetic number, because the mean of its divisors is an integer number (29285332).

Almost surely, 2^399303993 is an apocalyptic number.

399303993 is a gapful number since it is divisible by the number (33) formed by its first and last digit.

It is an amenable number.

399303993 is a deficient number, since it is larger than the sum of its proper divisors (186402647).

399303993 is an frugal number, since it uses more digits than its factorization.

399303993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9138 (or 9105 counting only the distinct ones).

The product of its (nonzero) digits is 531441, while the sum is 48.

The square root of 399303993 is about 19982.5922492554. The cubic root of 399303993 is about 736.3786996697.

The spelling of 399303993 in words is "three hundred ninety-nine million, three hundred three thousand, nine hundred ninety-three".