312891986 has 32 divisors (see below), whose sum is σ = 523800000. Its totient is φ = 138977280.

The previous prime is 312891979. The next prime is 312892007. The reversal of 312891986 is 689198213.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 312891986.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 249890 + ... + 251138.

It is an arithmetic number, because the mean of its divisors is an integer number (16368750).

Almost surely, 2^312891986 is an apocalyptic number.

312891986 is a deficient number, since it is larger than the sum of its proper divisors (210908014).

312891986 is a wasteful number, since it uses less digits than its factorization.

312891986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1514.

The product of its digits is 186624, while the sum is 47.

The square root of 312891986 is about 17688.7530934207. The cubic root of 312891986 is about 678.8880225834. Note that the first 3 decimals are identical.

It can be divided in two parts, 312 and 891986, that added together give a palindrome (892298).

The spelling of 312891986 in words is "three hundred twelve million, eight hundred ninety-one thousand, nine hundred eighty-six".