3091921 has 4 divisors (see below), whose sum is σ = 3533632. Its totient is φ = 2650212.

The previous prime is 3091919. The next prime is 3091939. The reversal of 3091921 is 1291903.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1291903 = 577 ⋅2239.

It is a cyclic number.

It is not a de Polignac number, because 3091921 - 2¹ = 3091919 is a prime.

It is a Duffinian number.

3091921 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3091901) 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, 220845 + ... + 220858.

It is an arithmetic number, because the mean of its divisors is an integer number (883408).

Almost surely, 2^3091921 is an apocalyptic number.

It is an amenable number.

3091921 is a deficient number, since it is larger than the sum of its proper divisors (441711).

3091921 is an equidigital number, since it uses as much as digits as its factorization.

3091921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441710.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 3091921 is about 1758.3859075868. The cubic root of 3091921 is about 145.6831968515.

The spelling of 3091921 in words is "three million, ninety-one thousand, nine hundred twenty-one".