1823989 has 4 divisors (see below), whose sum is σ = 1873324. Its totient is φ = 1774656.

The previous prime is 1823963. The next prime is 1823993. The reversal of 1823989 is 9893281.

1823989 = T₁₈₄ + T₁₈₅ + ... + T₂₅₇.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9893281 = 19 ⋅520699.

It can be written as a sum of positive squares in 2 ways, for example, as 756900 + 1067089 = 870^2 + 1033^2 .

It is a cyclic number.

It is not a de Polignac number, because 1823989 - 2⁵ = 1823957 is a prime.

It is a Duffinian number.

1823989 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1823999) 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, 24612 + ... + 24685.

It is an arithmetic number, because the mean of its divisors is an integer number (468331).

2^1823989 is an apocalyptic number.

It is an amenable number.

1823989 is a deficient number, since it is larger than the sum of its proper divisors (49335).

1823989 is an equidigital number, since it uses as much as digits as its factorization.

1823989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49334.

The product of its digits is 31104, while the sum is 40.

The square root of 1823989 is about 1350.5513688861. The cubic root of 1823989 is about 122.1820492703.

The spelling of 1823989 in words is "one million, eight hundred twenty-three thousand, nine hundred eighty-nine".