820949317709 has 2 divisors, whose sum is σ = 820949317710. Its totient is φ = 820949317708.

The previous prime is 820949317681. The next prime is 820949317781. The reversal of 820949317709 is 907713949028.

820949317709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 818463996100 + 2485321609 = 904690^2 + 49853^2 .

It is a cyclic number.

It is not a de Polignac number, because 820949317709 - 2²⁸ = 820680882253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820949517709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410474658854 + 410474658855.

It is an arithmetic number, because the mean of its divisors is an integer number (410474658855).

Almost surely, 2^820949317709 is an apocalyptic number.

It is an amenable number.

820949317709 is a deficient number, since it is larger than the sum of its proper divisors (1).

820949317709 is an equidigital number, since it uses as much as digits as its factorization.

820949317709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6858432, while the sum is 59.

The spelling of 820949317709 in words is "eight hundred twenty billion, nine hundred forty-nine million, three hundred seventeen thousand, seven hundred nine".