399290868 has 18 divisors (see below), whose sum is σ = 1009318674. Its totient is φ = 133096944.

The previous prime is 399290867. The next prime is 399290873. The reversal of 399290868 is 868092993.

It can be written as a sum of positive squares in only one way, i.e., 364504464 + 34786404 = 19092^2 + 5898^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399290861) 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 5 ways as a sum of consecutive naturals, for example, 5545671 + ... + 5545742.

Almost surely, 2^399290868 is an apocalyptic number.

It is an amenable number.

399290868 is an abundant number, since it is smaller than the sum of its proper divisors (610027806).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399290868 is a wasteful number, since it uses less digits than its factorization.

399290868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11091423 (or 11091418 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The square root of 399290868 is about 19982.2638357119. The cubic root of 399290868 is about 736.3706314005.

The spelling of 399290868 in words is "three hundred ninety-nine million, two hundred ninety thousand, eight hundred sixty-eight".