1231889 has 2 divisors, whose sum is σ = 1231890. Its totient is φ = 1231888.

The previous prime is 1231883. The next prime is 1231943. The reversal of 1231889 is 9881321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1227664 + 4225 = 1108^2 + 65^2 .

It is an emirp because it is prime and its reverse (9881321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1231889 - 2⁴ = 1231873 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1231883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615944 + 615945.

It is an arithmetic number, because the mean of its divisors is an integer number (615945).

2^1231889 is an apocalyptic number.

It is an amenable number.

1231889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231889 is an equidigital number, since it uses as much as digits as its factorization.

1231889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 32.

The square root of 1231889 is about 1109.9049508854. The cubic root of 1231889 is about 107.1989485770.

The spelling of 1231889 in words is "one million, two hundred thirty-one thousand, eight hundred eighty-nine".