646618 has 8 divisors (see below), whose sum is σ = 1108512. Its totient is φ = 277116.

The previous prime is 646609. The next prime is 646619. The reversal of 646618 is 816646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×646618² = 836229675848, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 646618.

It is not an unprimeable number, because it can be changed into a prime (646619) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 23080 + ... + 23107.

It is an arithmetic number, because the mean of its divisors is an integer number (138564).

2⁶⁴⁶⁶¹⁸ is an apocalyptic number.

646618 is a deficient number, since it is larger than the sum of its proper divisors (461894).

646618 is a wasteful number, since it uses less digits than its factorization.

646618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46196.

The product of its digits is 6912, while the sum is 31.

The square root of 646618 is about 804.1256120781. The cubic root of 646618 is about 86.4734122568.

The spelling of 646618 in words is "six hundred forty-six thousand, six hundred eighteen".