2145891 has 8 divisors (see below), whose sum is σ = 3121344. Its totient is φ = 1300520.

The previous prime is 2145853. The next prime is 2145937. The reversal of 2145891 is 1985412.

It is a happy number.

2145891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2145891 - 2⁶ = 2145827 is a prime.

2145891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2145821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32481 + ... + 32546.

It is an arithmetic number, because the mean of its divisors is an integer number (390168).

2^2145891 is an apocalyptic number.

2145891 is a deficient number, since it is larger than the sum of its proper divisors (975453).

2145891 is a wasteful number, since it uses less digits than its factorization.

2145891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65041.

The product of its digits is 2880, while the sum is 30.

The square root of 2145891 is about 1464.8860023906. The cubic root of 2145891 is about 128.9840134026.

It can be divided in two parts, 214 and 5891, that added together give a triangular number (6105 = T₁₁₀).

The spelling of 2145891 in words is "two million, one hundred forty-five thousand, eight hundred ninety-one".