1921589 has 4 divisors (see below), whose sum is σ = 1929324. Its totient is φ = 1913856.

The previous prime is 1921573. The next prime is 1921631. The reversal of 1921589 is 9851291.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1868689 + 52900 = 1367^2 + 230^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921589 - 2⁴ = 1921573 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921529) 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, 3482 + ... + 3995.

It is an arithmetic number, because the mean of its divisors is an integer number (482331).

2^1921589 is an apocalyptic number.

It is an amenable number.

1921589 is a deficient number, since it is larger than the sum of its proper divisors (7735).

1921589 is an equidigital number, since it uses as much as digits as its factorization.

1921589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7734.

The product of its digits is 6480, while the sum is 35.

The square root of 1921589 is about 1386.2139084571. The cubic root of 1921589 is about 124.3235782313.

The spelling of 1921589 in words is "one million, nine hundred twenty-one thousand, five hundred eighty-nine".