1668623 has 4 divisors (see below), whose sum is σ = 1820328. Its totient is φ = 1516920.

The previous prime is 1668619. The next prime is 1668629. The reversal of 1668623 is 3268661.

Added to its reverse (3268661) it gives a square (4937284 = 2222²).

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3268661 = 11 ⋅297151.

It is a cyclic number.

It is not a de Polignac number, because 1668623 - 2² = 1668619 is a prime.

It is a super-2 number, since 2×1668623² = 5568605432258, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1668623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668629) 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, 75836 + ... + 75857.

It is an arithmetic number, because the mean of its divisors is an integer number (455082).

2^1668623 is an apocalyptic number.

1668623 is a deficient number, since it is larger than the sum of its proper divisors (151705).

1668623 is a wasteful number, since it uses less digits than its factorization.

1668623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151704.

The product of its digits is 10368, while the sum is 32.

The square root of 1668623 is about 1291.7519111656. The cubic root of 1668623 is about 118.6094818036.

Adding to 1668623 its reverse (3268661), we get a square (4937284 = 2222²).

The spelling of 1668623 in words is "one million, six hundred sixty-eight thousand, six hundred twenty-three".