1866172 has 48 divisors (see below), whose sum is σ = 4177152. Its totient is φ = 708480.

The previous prime is 1866143. The next prime is 1866191. The reversal of 1866172 is 2716681.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22443 + ... + 22525.

It is an arithmetic number, because the mean of its divisors is an integer number (87024).

2^1866172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1866172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2088576).

1866172 is an abundant number, since it is smaller than the sum of its proper divisors (2310980).

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

1866172 is a wasteful number, since it uses less digits than its factorization.

1866172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178 (or 176 counting only the distinct ones).

The product of its digits is 4032, while the sum is 31.

The square root of 1866172 is about 1366.0790606696. The cubic root of 1866172 is about 123.1167727932.

The spelling of 1866172 in words is "one million, eight hundred sixty-six thousand, one hundred seventy-two".