3291891 has 4 divisors (see below), whose sum is σ = 4389192. Its totient is φ = 2194592.

The previous prime is 3291881. The next prime is 3291901. The reversal of 3291891 is 1981923.

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

It is an interprime number because it is at equal distance from previous prime (3291881) and next prime (3291901).

It is a cyclic number.

It is not a de Polignac number, because 3291891 - 2⁷ = 3291763 is a prime.

It is a D-number.

3291891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3291881) 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, 548646 + ... + 548651.

It is an arithmetic number, because the mean of its divisors is an integer number (1097298).

Almost surely, 2^3291891 is an apocalyptic number.

3291891 is the 1148-th centered pentagonal number.

3291891 is a deficient number, since it is larger than the sum of its proper divisors (1097301).

3291891 is a wasteful number, since it uses less digits than its factorization.

3291891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1097300.

The product of its digits is 3888, while the sum is 33.

The square root of 3291891 is about 1814.3569108640. The cubic root of 3291891 is about 148.7585085640.

The spelling of 3291891 in words is "three million, two hundred ninety-one thousand, eight hundred ninety-one".