2991863 has 8 divisors (see below), whose sum is σ = 3568128. Its totient is φ = 2452824.

The previous prime is 2991853. The next prime is 2991871. The reversal of 2991863 is 3681992.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2991863 - 2¹⁰ = 2990839 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2991803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9131 + ... + 9452.

It is an arithmetic number, because the mean of its divisors is an integer number (446016).

2^2991863 is an apocalyptic number.

2991863 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

2991863 is a deficient number, since it is larger than the sum of its proper divisors (576265).

2991863 is a wasteful number, since it uses less digits than its factorization.

2991863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18613.

The product of its digits is 23328, while the sum is 38.

The square root of 2991863 is about 1729.7002630514. The cubic root of 2991863 is about 144.0944435747.

The spelling of 2991863 in words is "two million, nine hundred ninety-one thousand, eight hundred sixty-three".