999869101321 has 2 divisors, whose sum is σ = 999869101322. Its totient is φ = 999869101320.

The previous prime is 999869101307. The next prime is 999869101391. The reversal of 999869101321 is 123101968999.

999869101321 = 707060² + 707061².

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 499935257721 + 499933843600 = 707061^2 + 707060^2 .

It is a cyclic number.

It is not a de Polignac number, because 999869101321 - 2⁷ = 999869101193 is a prime.

It is not a weakly prime, because it can be changed into another prime (999869101391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499934550660 + 499934550661.

It is an arithmetic number, because the mean of its divisors is an integer number (499934550661).

Almost surely, 2^999869101321 is an apocalyptic number.

999869101321 is the 707061-st centered square number.

It is an amenable number.

999869101321 is a deficient number, since it is larger than the sum of its proper divisors (1).

999869101321 is an equidigital number, since it uses as much as digits as its factorization.

999869101321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1889568, while the sum is 58.

The spelling of 999869101321 in words is "nine hundred ninety-nine billion, eight hundred sixty-nine million, one hundred one thousand, three hundred twenty-one".