1321831187 has 2 divisors, whose sum is σ = 1321831188. Its totient is φ = 1321831186.

The previous prime is 1321831157. The next prime is 1321831207. The reversal of 1321831187 is 7811381231.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1321831187 - 2¹⁰ = 1321830163 is a prime.

It is not a weakly prime, because it can be changed into another prime (1321831127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660915593 + 660915594.

It is an arithmetic number, because the mean of its divisors is an integer number (660915594).

Almost surely, 2^1321831187 is an apocalyptic number.

1321831187 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321831187 is an equidigital number, since it uses as much as digits as its factorization.

1321831187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 35.

The square root of 1321831187 is about 36356.9963968422. The cubic root of 1321831187 is about 1097.4683340023.

The spelling of 1321831187 in words is "one billion, three hundred twenty-one million, eight hundred thirty-one thousand, one hundred eighty-seven".