1320543989 has 2 divisors, whose sum is σ = 1320543990. Its totient is φ = 1320543988.

The previous prime is 1320543977. The next prime is 1320544067. The reversal of 1320543989 is 9893450231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1249056964 + 71487025 = 35342^2 + 8455^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320543989 - 2²⁴ = 1303766773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1320513989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660271994 + 660271995.

It is an arithmetic number, because the mean of its divisors is an integer number (660271995).

Almost surely, 2^1320543989 is an apocalyptic number.

It is an amenable number.

1320543989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320543989 is an equidigital number, since it uses as much as digits as its factorization.

1320543989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 1320543989 is about 36339.2898802384. The cubic root of 1320543989 is about 1097.1119804186. Note that the first 3 decimals are identical.

The spelling of 1320543989 in words is "one billion, three hundred twenty million, five hundred forty-three thousand, nine hundred eighty-nine".