1321775999 has 16 divisors (see below), whose sum is σ = 1380474144. Its totient is φ = 1264473600.

The previous prime is 1321775989. The next prime is 1321776019. The reversal of 1321775999 is 9995771231.

It is a cyclic number.

It is not a de Polignac number, because 1321775999 - 2⁸ = 1321775743 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321775999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321775909) 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 in 15 ways as a sum of consecutive naturals, for example, 1107347 + ... + 1108539.

It is an arithmetic number, because the mean of its divisors is an integer number (86279634).

Almost surely, 2^1321775999 is an apocalyptic number.

1321775999 is a deficient number, since it is larger than the sum of its proper divisors (58698145).

1321775999 is a wasteful number, since it uses less digits than its factorization.

1321775999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1738.

The product of its digits is 1071630, while the sum is 53.

The square root of 1321775999 is about 36356.2374153322. The cubic root of 1321775999 is about 1097.4530602603.

The spelling of 1321775999 in words is "one billion, three hundred twenty-one million, seven hundred seventy-five thousand, nine hundred ninety-nine".