399120906 has 8 divisors (see below), whose sum is σ = 798241824. Its totient is φ = 133040300.

The previous prime is 399120833. The next prime is 399120919. The reversal of 399120906 is 609021993.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

399120906 is an admirable number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 33260070 + ... + 33260081.

It is an arithmetic number, because the mean of its divisors is an integer number (99780228).

Almost surely, 2^399120906 is an apocalyptic number.

399120906 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

399120906 is a wasteful number, since it uses less digits than its factorization.

399120906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66520156.

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

The square root of 399120906 is about 19978.0105616150. The cubic root of 399120906 is about 736.2661354909.

The spelling of 399120906 in words is "three hundred ninety-nine million, one hundred twenty thousand, nine hundred six".