1321129189 has 2 divisors, whose sum is σ = 1321129190. Its totient is φ = 1321129188.

The previous prime is 1321129171. The next prime is 1321129267. The reversal of 1321129189 is 9819211231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 923126689 + 398002500 = 30383^2 + 19950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321129189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321129889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660564594 + 660564595.

It is an arithmetic number, because the mean of its divisors is an integer number (660564595).

Almost surely, 2^1321129189 is an apocalyptic number.

It is an amenable number.

1321129189 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321129189 is an equidigital number, since it uses as much as digits as its factorization.

1321129189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 37.

The square root of 1321129189 is about 36347.3408793546. The cubic root of 1321129189 is about 1097.2740184678.

The spelling of 1321129189 in words is "one billion, three hundred twenty-one million, one hundred twenty-nine thousand, one hundred eighty-nine".