1668493 has 4 divisors (see below), whose sum is σ = 1700028. Its totient is φ = 1636960.

The previous prime is 1668481. The next prime is 1668503. The reversal of 1668493 is 3948661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3948661 = 223 ⋅17707.

It can be written as a sum of positive squares in 2 ways, for example, as 580644 + 1087849 = 762^2 + 1043^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668493 - 2¹⁷ = 1537421 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668473) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15688 + ... + 15793.

It is an arithmetic number, because the mean of its divisors is an integer number (425007).

2^1668493 is an apocalyptic number.

It is an amenable number.

1668493 is a deficient number, since it is larger than the sum of its proper divisors (31535).

1668493 is an equidigital number, since it uses as much as digits as its factorization.

1668493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31534.

The product of its digits is 31104, while the sum is 37.

The square root of 1668493 is about 1291.7015909257. The cubic root of 1668493 is about 118.6064014927.

The spelling of 1668493 in words is "one million, six hundred sixty-eight thousand, four hundred ninety-three".