399798909 has 32 divisors (see below), whose sum is σ = 619054080. Its totient is φ = 257891040.

The previous prime is 399798899. The next prime is 399798923. The reversal of 399798909 is 909897993.

It is not a de Polignac number, because 399798909 - 2¹⁹ = 399274621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399796909) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 64849 + ... + 70745.

It is an arithmetic number, because the mean of its divisors is an integer number (19345440).

Almost surely, 2^399798909 is an apocalyptic number.

It is an amenable number.

399798909 is a deficient number, since it is larger than the sum of its proper divisors (219255171).

399798909 is an frugal number, since it uses more digits than its factorization.

399798909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5949 (or 5931 counting only the distinct ones).

The product of its (nonzero) digits is 9920232, while the sum is 63.

The square root of 399798909 is about 19994.9720930038. The cubic root of 399798909 is about 736.6828081019.

The spelling of 399798909 in words is "three hundred ninety-nine million, seven hundred ninety-eight thousand, nine hundred nine".