1668531 has 4 divisors (see below), whose sum is σ = 2224712. Its totient is φ = 1112352.

The previous prime is 1668521. The next prime is 1668539. The reversal of 1668531 is 1358661.

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

It is not a de Polignac number, because 1668531 - 2⁶ = 1668467 is a prime.

It is a super-2 number, since 2×1668531² = 5567991395922, which contains 22 as substring.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668539) 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, 278086 + ... + 278091.

It is an arithmetic number, because the mean of its divisors is an integer number (556178).

2^1668531 is an apocalyptic number.

1668531 is a deficient number, since it is larger than the sum of its proper divisors (556181).

1668531 is an equidigital number, since it uses as much as digits as its factorization.

1668531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556180.

The product of its digits is 4320, while the sum is 30.

The square root of 1668531 is about 1291.7163001217. The cubic root of 1668531 is about 118.6073019078.

The spelling of 1668531 in words is "one million, six hundred sixty-eight thousand, five hundred thirty-one".