1666090 has 8 divisors (see below), whose sum is σ = 2998980. Its totient is φ = 666432.

The previous prime is 1666081. The next prime is 1666111. The reversal of 1666090 is 906661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1371241 + 294849 = 1171^2 + 543^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83295 + ... + 83314.

2^1666090 is an apocalyptic number.

1666090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1666090 is a deficient number, since it is larger than the sum of its proper divisors (1332890).

1666090 is a wasteful number, since it uses less digits than its factorization.

1666090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166616.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 1666090 is about 1290.7710873737. The cubic root of 1666090 is about 118.5494342936.

The spelling of 1666090 in words is "one million, six hundred sixty-six thousand, ninety".