1321249771 has 2 divisors, whose sum is σ = 1321249772. Its totient is φ = 1321249770.

The previous prime is 1321249763. The next prime is 1321249807. The reversal of 1321249771 is 1779421231.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1321249771 - 2³ = 1321249763 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321249771.

It is not a weakly prime, because it can be changed into another prime (1321249751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660624885 + 660624886.

It is an arithmetic number, because the mean of its divisors is an integer number (660624886).

Almost surely, 2^1321249771 is an apocalyptic number.

1321249771 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321249771 is an equidigital number, since it uses as much as digits as its factorization.

1321249771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 37.

The square root of 1321249771 is about 36348.9995873339. Note that the first 3 decimals coincide. The cubic root of 1321249771 is about 1097.3074008883.

The spelling of 1321249771 in words is "one billion, three hundred twenty-one million, two hundred forty-nine thousand, seven hundred seventy-one".