1986667 has 4 divisors (see below), whose sum is σ = 1989576. Its totient is φ = 1983760.

The previous prime is 1986631. The next prime is 1986679. The reversal of 1986667 is 7666891.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7666891 = 461 ⋅16631.

It is a cyclic number.

It is not a de Polignac number, because 1986667 - 2⁷ = 1986539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1986067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192 + ... + 2002.

It is an arithmetic number, because the mean of its divisors is an integer number (497394).

2^1986667 is an apocalyptic number.

1986667 is a deficient number, since it is larger than the sum of its proper divisors (2909).

1986667 is a wasteful number, since it uses less digits than its factorization.

1986667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2908.

The product of its digits is 108864, while the sum is 43.

The square root of 1986667 is about 1409.4917523703. The cubic root of 1986667 is about 125.7115050669.

The spelling of 1986667 in words is "one million, nine hundred eighty-six thousand, six hundred sixty-seven".