1661166 has 48 divisors (see below), whose sum is σ = 4018560. Its totient is φ = 492480.

The previous prime is 1661161. The next prime is 1661173. The reversal of 1661166 is 6611661.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7140 + ... + 7368.

It is an arithmetic number, because the mean of its divisors is an integer number (83720).

2^1661166 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661166, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2009280).

1661166 is an abundant number, since it is smaller than the sum of its proper divisors (2357394).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661166 is a wasteful number, since it uses less digits than its factorization.

1661166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 278 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 1661166 is about 1288.8622889975. The cubic root of 1661166 is about 118.4325311603.

The spelling of 1661166 in words is "one million, six hundred sixty-one thousand, one hundred sixty-six".