1321789 has 4 divisors (see below), whose sum is σ = 1510624. Its totient is φ = 1132956.

The previous prime is 1321769. The next prime is 1321813. The reversal of 1321789 is 9871231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9871231 = 59 ⋅167309.

It is a cyclic number.

It is not a de Polignac number, because 1321789 - 2⁵ = 1321757 is a prime.

It is a Duffinian number.

1321789 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321789.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321729) 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, 94407 + ... + 94420.

It is an arithmetic number, because the mean of its divisors is an integer number (377656).

2^1321789 is an apocalyptic number.

It is an amenable number.

1321789 is a deficient number, since it is larger than the sum of its proper divisors (188835).

1321789 is an equidigital number, since it uses as much as digits as its factorization.

1321789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188834.

The product of its digits is 3024, while the sum is 31.

The square root of 1321789 is about 1149.6908280055. The cubic root of 1321789 is about 109.7456658434.

The spelling of 1321789 in words is "one million, three hundred twenty-one thousand, seven hundred eighty-nine".