6391618 has 4 divisors (see below), whose sum is σ = 9587430. Its totient is φ = 3195808.

The previous prime is 6391607. The next prime is 6391663. The reversal of 6391618 is 8161936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 5076009 + 1315609 = 2253^2 + 1147^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1597903 + ... + 1597906.

Almost surely, 2^6391618 is an apocalyptic number.

6391618 is a deficient number, since it is larger than the sum of its proper divisors (3195812).

6391618 is a wasteful number, since it uses less digits than its factorization.

6391618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3195811.

The product of its digits is 7776, while the sum is 34.

The square root of 6391618 is about 2528.1649471504. The cubic root of 6391618 is about 185.5824641887.

The spelling of 6391618 in words is "six million, three hundred ninety-one thousand, six hundred eighteen".