1666726 has 4 divisors (see below), whose sum is σ = 2500092. Its totient is φ = 833362.

The previous prime is 1666711. The next prime is 1666727. The reversal of 1666726 is 6276661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6276661 = 229 ⋅27409.

It is a junction number, because it is equal to n+sod(n) for n = 1666691 and 1666700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416680 + ... + 416683.

It is an arithmetic number, because the mean of its divisors is an integer number (625023).

2^1666726 is an apocalyptic number.

1666726 is a deficient number, since it is larger than the sum of its proper divisors (833366).

1666726 is an equidigital number, since it uses as much as digits as its factorization.

1666726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833365.

The product of its digits is 18144, while the sum is 34.

The square root of 1666726 is about 1291.0174282325. The cubic root of 1666726 is about 118.5645170819.

The spelling of 1666726 in words is "one million, six hundred sixty-six thousand, seven hundred twenty-six".