1881666 has 12 divisors (see below), whose sum is σ = 4076982. Its totient is φ = 627216.

The previous prime is 1881641. The next prime is 1881697. The reversal of 1881666 is 6661881.

It can be written as a sum of positive squares in only one way, i.e., 1879641 + 2025 = 1371^2 + 45^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1881666.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 52251 + ... + 52286.

2^1881666 is an apocalyptic number.

1881666 is an abundant number, since it is smaller than the sum of its proper divisors (2195316).

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

1881666 is a wasteful number, since it uses less digits than its factorization.

1881666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104545 (or 104542 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 1881666 is about 1371.7383132362. The cubic root of 1881666 is about 123.4565621686.

The spelling of 1881666 in words is "one million, eight hundred eighty-one thousand, six hundred sixty-six".