398840985 has 12 divisors (see below), whose sum is σ = 691324452. Its totient is φ = 212715168.

The previous prime is 398840977. The next prime is 398840987. The reversal of 398840985 is 589048893.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 143352729 + 255488256 = 11973^2 + 15984^2 .

It is not a de Polignac number, because 398840985 - 2³ = 398840977 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (398840987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4431522 + ... + 4431611.

It is an arithmetic number, because the mean of its divisors is an integer number (57610371).

Almost surely, 2^398840985 is an apocalyptic number.

It is an amenable number.

398840985 is a deficient number, since it is larger than the sum of its proper divisors (292483467).

398840985 is a wasteful number, since it uses less digits than its factorization.

398840985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8863144 (or 8863141 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The square root of 398840985 is about 19971.0036052273. The cubic root of 398840985 is about 736.0939699892.

The spelling of 398840985 in words is "three hundred ninety-eight million, eight hundred forty thousand, nine hundred eighty-five".