1986091 has 4 divisors (see below), whose sum is σ = 2001384. Its totient is φ = 1970800.

The previous prime is 1986071. The next prime is 1986097. The reversal of 1986091 is 1906891.

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

It is a cyclic number.

It is not a de Polignac number, because 1986091 - 2¹¹ = 1984043 is a prime.

It is a Duffinian number.

1986091 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1986097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7450 + ... + 7711.

It is an arithmetic number, because the mean of its divisors is an integer number (500346).

2^1986091 is an apocalyptic number.

1986091 is a deficient number, since it is larger than the sum of its proper divisors (15293).

1986091 is a wasteful number, since it uses less digits than its factorization.

1986091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15292.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 1986091 is about 1409.2874085863. The cubic root of 1986091 is about 125.6993545948.

The spelling of 1986091 in words is "one million, nine hundred eighty-six thousand, ninety-one".