1881289 has 2 divisors, whose sum is σ = 1881290. Its totient is φ = 1881288.

The previous prime is 1881277. The next prime is 1881307. The reversal of 1881289 is 9821881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1040400 + 840889 = 1020^2 + 917^2 .

It is a cyclic number.

It is not a de Polignac number, because 1881289 - 2⁷ = 1881161 is a prime.

It is not a weakly prime, because it can be changed into another prime (1881389) 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, 940644 + 940645.

It is an arithmetic number, because the mean of its divisors is an integer number (940645).

2^1881289 is an apocalyptic number.

It is an amenable number.

1881289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1881289 is an equidigital number, since it uses as much as digits as its factorization.

1881289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9216, while the sum is 37.

The square root of 1881289 is about 1371.6008894719. The cubic root of 1881289 is about 123.4483165974.

The spelling of 1881289 in words is "one million, eight hundred eighty-one thousand, two hundred eighty-nine".