399016209 has 4 divisors (see below), whose sum is σ = 532021616. Its totient is φ = 266010804.

The previous prime is 399016201. The next prime is 399016217. The reversal of 399016209 is 902610993.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (399016201) and next prime (399016217).

It is not a de Polignac number, because 399016209 - 2³ = 399016201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399016201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66502699 + ... + 66502704.

It is an arithmetic number, because the mean of its divisors is an integer number (133005404).

Almost surely, 2^399016209 is an apocalyptic number.

It is an amenable number.

399016209 is a deficient number, since it is larger than the sum of its proper divisors (133005407).

399016209 is a wasteful number, since it uses less digits than its factorization.

399016209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133005406.

The product of its (nonzero) digits is 26244, while the sum is 39.

The square root of 399016209 is about 19975.3900838006. The cubic root of 399016209 is about 736.2017509935.

The spelling of 399016209 in words is "three hundred ninety-nine million, sixteen thousand, two hundred nine".