1320989 has 4 divisors (see below), whose sum is σ = 1323420. Its totient is φ = 1318560.

The previous prime is 1320983. The next prime is 1321007. The reversal of 1320989 is 9890231.

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 917764 + 403225 = 958^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320989 - 2⁴ = 1320973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320983) 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, 17 + ... + 1625.

It is an arithmetic number, because the mean of its divisors is an integer number (330855).

2^1320989 is an apocalyptic number.

It is an amenable number.

1320989 is a deficient number, since it is larger than the sum of its proper divisors (2431).

1320989 is an equidigital number, since it uses as much as digits as its factorization.

1320989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2430.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 1320989 is about 1149.3428557223. The cubic root of 1320989 is about 109.7235205411.

The spelling of 1320989 in words is "one million, three hundred twenty thousand, nine hundred eighty-nine".