1666623 has 16 divisors (see below), whose sum is σ = 2673920. Its totient is φ = 902016.

The previous prime is 1666619. The next prime is 1666627. The reversal of 1666623 is 3266661.

It is an interprime number because it is at equal distance from previous prime (1666619) and next prime (1666627).

It is not a de Polignac number, because 1666623 - 2² = 1666619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666627) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1690 + ... + 2487.

It is an arithmetic number, because the mean of its divisors is an integer number (167120).

2^1666623 is an apocalyptic number.

1666623 is a deficient number, since it is larger than the sum of its proper divisors (1007297).

1666623 is a wasteful number, since it uses less digits than its factorization.

1666623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4206.

The product of its digits is 7776, while the sum is 30.

The square root of 1666623 is about 1290.9775365978. The cubic root of 1666623 is about 118.5620746895.

The spelling of 1666623 in words is "one million, six hundred sixty-six thousand, six hundred twenty-three".