1980289 has 2 divisors, whose sum is σ = 1980290. Its totient is φ = 1980288.

The previous prime is 1980283. The next prime is 1980301. The reversal of 1980289 is 9820891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1912689 + 67600 = 1383^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1980289 - 2³ = 1980281 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1980281) 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 as a sum of consecutive naturals, namely, 990144 + 990145.

It is an arithmetic number, because the mean of its divisors is an integer number (990145).

2^1980289 is an apocalyptic number.

It is an amenable number.

1980289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1980289 is an equidigital number, since it uses as much as digits as its factorization.

1980289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 1980289 is about 1407.2274158785. The cubic root of 1980289 is about 125.5768326845.

It can be divided in two parts, 19802 and 89, that added together give a palindrome (19891).

The spelling of 1980289 in words is "one million, nine hundred eighty thousand, two hundred eighty-nine".