1668645 has 24 divisors (see below), whose sum is σ = 3156192. Its totient is φ = 808800.

The previous prime is 1668629. The next prime is 1668647. The reversal of 1668645 is 5468661.

1668645 is a `hidden beast` number, since 1 + 6 + 6 + 8 + 645 = 666.

It is not a de Polignac number, because 1668645 - 2⁴ = 1668629 is a prime.

It is a super-2 number, since 2×1668645² = 5568752272050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668647) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 1191 + ... + 2180.

It is an arithmetic number, because the mean of its divisors is an integer number (131508).

2^1668645 is an apocalyptic number.

1668645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1668645 is a deficient number, since it is larger than the sum of its proper divisors (1487547).

1668645 is a wasteful number, since it uses less digits than its factorization.

1668645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3393 (or 3390 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1668645 is about 1291.7604267046. The cubic root of 1668645 is about 118.6100030712.

The spelling of 1668645 in words is "one million, six hundred sixty-eight thousand, six hundred forty-five".