2165986 has 4 divisors (see below), whose sum is σ = 3248982. Its totient is φ = 1082992.

The previous prime is 2165971. The next prime is 2166007. The reversal of 2165986 is 6895612.

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

It can be written as a sum of positive squares in only one way, i.e., 1946025 + 219961 = 1395^2 + 469^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 541495 + ... + 541498.

2^2165986 is an apocalyptic number.

2165986 is a deficient number, since it is larger than the sum of its proper divisors (1082996).

2165986 is a wasteful number, since it uses less digits than its factorization.

2165986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082995.

The product of its digits is 25920, while the sum is 37.

The square root of 2165986 is about 1471.7289152558. The cubic root of 2165986 is about 129.3853828007.

The spelling of 2165986 in words is "two million, one hundred sixty-five thousand, nine hundred eighty-six".