8765699219821 has 2 divisors, whose sum is σ = 8765699219822. Its totient is φ = 8765699219820.

The previous prime is 8765699219707. The next prime is 8765699219891. The reversal of 8765699219821 is 1289129965678.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8616074149225 + 149625070596 = 2935315^2 + 386814^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8765699219821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8765699219891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4382849609910 + 4382849609911.

It is an arithmetic number, because the mean of its divisors is an integer number (4382849609911).

Almost surely, 2^{8765699219821} is an apocalyptic number.

It is an amenable number.

8765699219821 is a deficient number, since it is larger than the sum of its proper divisors (1).

8765699219821 is an equidigital number, since it uses as much as digits as its factorization.

8765699219821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 235146240, while the sum is 73.

The spelling of 8765699219821 in words is "eight trillion, seven hundred sixty-five billion, six hundred ninety-nine million, two hundred nineteen thousand, eight hundred twenty-one".