2991787 has 4 divisors (see below), whose sum is σ = 2996136. Its totient is φ = 2987440.

The previous prime is 2991773. The next prime is 2991803. The reversal of 2991787 is 7871992.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2991787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2991707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 889 + ... + 2602.

It is an arithmetic number, because the mean of its divisors is an integer number (749034).

2^2991787 is an apocalyptic number.

2991787 is a deficient number, since it is larger than the sum of its proper divisors (4349).

2991787 is an equidigital number, since it uses as much as digits as its factorization.

2991787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4348.

The product of its digits is 63504, while the sum is 43.

The square root of 2991787 is about 1729.6782937876. The cubic root of 2991787 is about 144.0932234575.

The spelling of 2991787 in words is "two million, nine hundred ninety-one thousand, seven hundred eighty-seven".