668915 has 16 divisors (see below), whose sum is σ = 889056. Its totient is φ = 480000.

The previous prime is 668903. The next prime is 668929. The reversal of 668915 is 519866.

It is not a de Polignac number, because 668915 - 2⁶ = 668851 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2540 + ... + 2790.

It is an arithmetic number, because the mean of its divisors is an integer number (55566).

2⁶⁶⁸⁹¹⁵ is an apocalyptic number.

668915 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

668915 is a deficient number, since it is larger than the sum of its proper divisors (220141).

668915 is a wasteful number, since it uses less digits than its factorization.

668915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310.

The product of its digits is 12960, while the sum is 35.

The square root of 668915 is about 817.8722394115. The cubic root of 668915 is about 87.4561412851.

It can be divided in two parts, 6 and 68915, that added together give a cube (68921 = 41³).

The spelling of 668915 in words is "six hundred sixty-eight thousand, nine hundred fifteen".