399191091 has 8 divisors (see below), whose sum is σ = 573197520. Its totient is φ = 245656032.

The previous prime is 399191063. The next prime is 399191101. The reversal of 399191091 is 190191993.

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

It is not a de Polignac number, because 399191091 - 2⁷ = 399190963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (399191021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5117796 + ... + 5117873.

It is an arithmetic number, because the mean of its divisors is an integer number (71649690).

Almost surely, 2^399191091 is an apocalyptic number.

399191091 is a deficient number, since it is larger than the sum of its proper divisors (174006429).

399191091 is a wasteful number, since it uses less digits than its factorization.

399191091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10235685.

The product of its (nonzero) digits is 19683, while the sum is 42.

The square root of 399191091 is about 19979.7670406839. The cubic root of 399191091 is about 736.3092901752.

The spelling of 399191091 in words is "three hundred ninety-nine million, one hundred ninety-one thousand, ninety-one".