2145491 has 4 divisors (see below), whose sum is σ = 2149152. Its totient is φ = 2141832.

The previous prime is 2145487. The next prime is 2145497. The reversal of 2145491 is 1945412.

2145491 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.

It is a cyclic number.

It is not a de Polignac number, because 2145491 - 2² = 2145487 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2145491.

It is not an unprimeable number, because it can be changed into a prime (2145497) 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 3 ways as a sum of consecutive naturals, for example, 731 + ... + 2196.

It is an arithmetic number, because the mean of its divisors is an integer number (537288).

2^2145491 is an apocalyptic number.

2145491 is a deficient number, since it is larger than the sum of its proper divisors (3661).

2145491 is an equidigital number, since it uses as much as digits as its factorization.

2145491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3660.

The product of its digits is 1440, while the sum is 26.

The square root of 2145491 is about 1464.7494666324. The cubic root of 2145491 is about 128.9759985793.

The spelling of 2145491 in words is "two million, one hundred forty-five thousand, four hundred ninety-one".