668415 has 16 divisors (see below), whose sum is σ = 1166976. Its totient is φ = 324000.

The previous prime is 668407. The next prime is 668417. The reversal of 668415 is 514866.

It is not a de Polignac number, because 668415 - 2³ = 668407 is a prime.

It is a super-2 number, since 2×668415² = 893557224450, which contains 22 as substring.

It is an Ulam number.

668415 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668417) 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 15 ways as a sum of consecutive naturals, for example, 1861 + ... + 2190.

It is an arithmetic number, because the mean of its divisors is an integer number (72936).

2⁶⁶⁸⁴¹⁵ is an apocalyptic number.

668415 is a deficient number, since it is larger than the sum of its proper divisors (498561).

668415 is a wasteful number, since it uses less digits than its factorization.

668415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4070.

The product of its digits is 5760, while the sum is 30.

The square root of 668415 is about 817.5665110558. The cubic root of 668415 is about 87.4343453068.

The spelling of 668415 in words is "six hundred sixty-eight thousand, four hundred fifteen".