10391891 has 4 divisors (see below), whose sum is σ = 10409784. Its totient is φ = 10374000.

The previous prime is 10391873. The next prime is 10391893. The reversal of 10391891 is 19819301.

10391891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19819301 = 3191 ⋅6211.

It is a cyclic number.

It is not a de Polignac number, because 10391891 - 2⁶ = 10391827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10391893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8045 + ... + 9246.

It is an arithmetic number, because the mean of its divisors is an integer number (2602446).

Almost surely, 2^10391891 is an apocalyptic number.

10391891 is a deficient number, since it is larger than the sum of its proper divisors (17893).

10391891 is an equidigital number, since it uses as much as digits as its factorization.

10391891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17892.

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 10391891 is about 3223.6456070728. The cubic root of 10391891 is about 218.2218304195.

The spelling of 10391891 in words is "ten million, three hundred ninety-one thousand, eight hundred ninety-one".