2686991 has 4 divisors (see below), whose sum is σ = 2691792. Its totient is φ = 2682192.

The previous prime is 2686979. The next prime is 2686993. The reversal of 2686991 is 1996862.

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 2686991 - 2¹⁰ = 2685967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2686993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1430 + ... + 2723.

It is an arithmetic number, because the mean of its divisors is an integer number (672948).

2^2686991 is an apocalyptic number.

2686991 is a deficient number, since it is larger than the sum of its proper divisors (4801).

2686991 is an equidigital number, since it uses as much as digits as its factorization.

2686991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4800.

The product of its digits is 46656, while the sum is 41.

The square root of 2686991 is about 1639.2043801796. The cubic root of 2686991 is about 139.0236662428.

The spelling of 2686991 in words is "two million, six hundred eighty-six thousand, nine hundred ninety-one".