399391145 has 4 divisors (see below), whose sum is σ = 479269380. Its totient is φ = 319512912.

The previous prime is 399391141. The next prime is 399391163. The reversal of 399391145 is 541193993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 235346281 + 164044864 = 15341^2 + 12808^2 .

It is a cyclic number.

It is not a de Polignac number, because 399391145 - 2² = 399391141 is a prime.

It is a super-2 number, since 2×399391145² = 319026573408822050, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 399391096 and 399391105.

It is not an unprimeable number, because it can be changed into a prime (399391141) 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, 39939110 + ... + 39939119.

It is an arithmetic number, because the mean of its divisors is an integer number (119817345).

Almost surely, 2^399391145 is an apocalyptic number.

It is an amenable number.

399391145 is a deficient number, since it is larger than the sum of its proper divisors (79878235).

399391145 is an equidigital number, since it uses as much as digits as its factorization.

399391145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79878234.

The product of its digits is 131220, while the sum is 44.

The square root of 399391145 is about 19984.7728283311. The cubic root of 399391145 is about 736.4322697225.

The spelling of 399391145 in words is "three hundred ninety-nine million, three hundred ninety-one thousand, one hundred forty-five".