1321738993 has 2 divisors, whose sum is σ = 1321738994. Its totient is φ = 1321738992.

The previous prime is 1321738991. The next prime is 1321738997. The reversal of 1321738993 is 3998371231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1100116224 + 221622769 = 33168^2 + 14887^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321738993 - 2¹ = 1321738991 is a prime.

Together with 1321738991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1321738991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660869496 + 660869497.

It is an arithmetic number, because the mean of its divisors is an integer number (660869497).

Almost surely, 2^1321738993 is an apocalyptic number.

It is an amenable number.

1321738993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321738993 is an equidigital number, since it uses as much as digits as its factorization.

1321738993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 46.

The square root of 1321738993 is about 36355.7284757162. The cubic root of 1321738993 is about 1097.4428183013.

The spelling of 1321738993 in words is "one billion, three hundred twenty-one million, seven hundred thirty-eight thousand, nine hundred ninety-three".