822720989 has 2 divisors, whose sum is σ = 822720990. Its totient is φ = 822720988.

The previous prime is 822720929. The next prime is 822721019. The reversal of 822720989 is 989027228.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 655872100 + 166848889 = 25610^2 + 12917^2 .

It is a cyclic number.

It is not a de Polignac number, because 822720989 - 2⁸ = 822720733 is a prime.

It is a super-2 number, since 2×822720989² = 1353739651482276242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (822720929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411360494 + 411360495.

It is an arithmetic number, because the mean of its divisors is an integer number (411360495).

Almost surely, 2^822720989 is an apocalyptic number.

It is an amenable number.

822720989 is a deficient number, since it is larger than the sum of its proper divisors (1).

822720989 is an equidigital number, since it uses as much as digits as its factorization.

822720989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 47.

The square root of 822720989 is about 28683.1133073103. The cubic root of 822720989 is about 937.0243115412.

The spelling of 822720989 in words is "eight hundred twenty-two million, seven hundred twenty thousand, nine hundred eighty-nine".