398139985 has 16 divisors (see below), whose sum is σ = 502356240. Its totient is φ = 302480640.

The previous prime is 398139941. The next prime is 398140007. The reversal of 398139985 is 589931893.

It can be written as a sum of positive squares in 8 ways, for example, as 153561664 + 244578321 = 12392^2 + 15639^2 .

It is not a de Polignac number, because 398139985 - 2¹¹ = 398137937 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13662 + ... + 31351.

It is an arithmetic number, because the mean of its divisors is an integer number (31397265).

Almost surely, 2^398139985 is an apocalyptic number.

It is an amenable number.

398139985 is a deficient number, since it is larger than the sum of its proper divisors (104216255).

398139985 is a wasteful number, since it uses less digits than its factorization.

398139985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45108.

The product of its digits is 2099520, while the sum is 55.

The square root of 398139985 is about 19953.4454418278. The cubic root of 398139985 is about 735.6624659604.

The spelling of 398139985 in words is "three hundred ninety-eight million, one hundred thirty-nine thousand, nine hundred eighty-five".