399022121 has 4 divisors (see below), whose sum is σ = 401047812. Its totient is φ = 396996432.

The previous prime is 399022109. The next prime is 399022123. The reversal of 399022121 is 121220993.

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 320947225 + 78074896 = 17915^2 + 8836^2 .

It is a cyclic number.

It is not a de Polignac number, because 399022121 - 2¹⁰ = 399021097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399022123) by changing a digit.

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, 1012550 + ... + 1012943.

It is an arithmetic number, because the mean of its divisors is an integer number (100261953).

Almost surely, 2^399022121 is an apocalyptic number.

It is an amenable number.

399022121 is a deficient number, since it is larger than the sum of its proper divisors (2025691).

399022121 is a wasteful number, since it uses less digits than its factorization.

399022121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2025690.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 399022121 is about 19975.5380653438. The cubic root of 399022121 is about 736.2053869387.

The spelling of 399022121 in words is "three hundred ninety-nine million, twenty-two thousand, one hundred twenty-one".