1666423 has 8 divisors (see below), whose sum is σ = 1829520. Its totient is φ = 1505280.

The previous prime is 1666421. The next prime is 1666429. The reversal of 1666423 is 3246661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1666423 - 2¹ = 1666421 is a prime.

It is a super-2 number, since 2×1666423² = 5553931229858, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1666391 and 1666400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1783 + ... + 2551.

It is an arithmetic number, because the mean of its divisors is an integer number (228690).

2^1666423 is an apocalyptic number.

1666423 is a deficient number, since it is larger than the sum of its proper divisors (163097).

1666423 is a wasteful number, since it uses less digits than its factorization.

1666423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 977.

The product of its digits is 5184, while the sum is 28.

The square root of 1666423 is about 1290.9000735921. The cubic root of 1666423 is about 118.5573318925.

The spelling of 1666423 in words is "one million, six hundred sixty-six thousand, four hundred twenty-three".