399069091 has 4 divisors (see below), whose sum is σ = 399110800. Its totient is φ = 399027384.

The previous prime is 399069089. The next prime is 399069109. The reversal of 399069091 is 190960993.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 399069091 - 2¹ = 399069089 is a prime.

It is a super-2 number, since 2×399069091² = 318512278783132562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399069491) 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 3 ways as a sum of consecutive naturals, for example, 1450 + ... + 28288.

It is an arithmetic number, because the mean of its divisors is an integer number (99777700).

Almost surely, 2^399069091 is an apocalyptic number.

399069091 is a deficient number, since it is larger than the sum of its proper divisors (41709).

399069091 is a wasteful number, since it uses less digits than its factorization.

399069091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41708.

The product of its (nonzero) digits is 118098, while the sum is 46.

The square root of 399069091 is about 19976.7137187276. The cubic root of 399069091 is about 736.2342727310.

The spelling of 399069091 in words is "three hundred ninety-nine million, sixty-nine thousand, ninety-one".