398865646 has 16 divisors (see below), whose sum is σ = 612638208. Its totient is φ = 194707800.

The previous prime is 398865637. The next prime is 398865647. The reversal of 398865646 is 646568893.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398865647) 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 7 ways as a sum of consecutive naturals, for example, 991 + ... + 28261.

It is an arithmetic number, because the mean of its divisors is an integer number (38289888).

Almost surely, 2^398865646 is an apocalyptic number.

398865646 is a deficient number, since it is larger than the sum of its proper divisors (213772562).

398865646 is a wasteful number, since it uses less digits than its factorization.

398865646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27447.

The product of its digits is 7464960, while the sum is 55.

The square root of 398865646 is about 19971.6210158314. The cubic root of 398865646 is about 736.1091409804.

The spelling of 398865646 in words is "three hundred ninety-eight million, eight hundred sixty-five thousand, six hundred forty-six".