1668239 has 4 divisors (see below), whose sum is σ = 1678056. Its totient is φ = 1658424.

The previous prime is 1668229. The next prime is 1668241. The reversal of 1668239 is 9328661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9328661 = 1931 ⋅4831.

It is a cyclic number.

It is not a de Polignac number, because 1668239 - 2¹⁶ = 1602703 is a prime.

It is a super-2 number, since 2×1668239² = 5566042722242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1668199 and 1668208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668229) 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, 4649 + ... + 4994.

It is an arithmetic number, because the mean of its divisors is an integer number (419514).

2^1668239 is an apocalyptic number.

1668239 is a deficient number, since it is larger than the sum of its proper divisors (9817).

1668239 is an equidigital number, since it uses as much as digits as its factorization.

1668239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9816.

The product of its digits is 15552, while the sum is 35.

The square root of 1668239 is about 1291.6032672613. The cubic root of 1668239 is about 118.6003825772.

The spelling of 1668239 in words is "one million, six hundred sixty-eight thousand, two hundred thirty-nine".