1663726 has 4 divisors (see below), whose sum is σ = 2495592. Its totient is φ = 831862.

The previous prime is 1663721. The next prime is 1663747. The reversal of 1663726 is 6273661.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415930 + ... + 415933.

It is an arithmetic number, because the mean of its divisors is an integer number (623898).

2^1663726 is an apocalyptic number.

1663726 is a deficient number, since it is larger than the sum of its proper divisors (831866).

1663726 is an equidigital number, since it uses as much as digits as its factorization.

1663726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831865.

The product of its digits is 9072, while the sum is 31.

The square root of 1663726 is about 1289.8550306139. The cubic root of 1663726 is about 118.4933381812.

The spelling of 1663726 in words is "one million, six hundred sixty-three thousand, seven hundred twenty-six".