22778606821 has 2 divisors, whose sum is σ = 22778606822. Its totient is φ = 22778606820.

The previous prime is 22778606819. The next prime is 22778606831. The reversal of 22778606821 is 12860687722.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22096822500 + 681784321 = 148650^2 + 26111^2 .

It is a cyclic number.

It is not a de Polignac number, because 22778606821 - 2¹ = 22778606819 is a prime.

Together with 22778606819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22778606831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11389303410 + 11389303411.

It is an arithmetic number, because the mean of its divisors is an integer number (11389303411).

Almost surely, 2^22778606821 is an apocalyptic number.

It is an amenable number.

22778606821 is a deficient number, since it is larger than the sum of its proper divisors (1).

22778606821 is an equidigital number, since it uses as much as digits as its factorization.

22778606821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 903168, while the sum is 49.

The spelling of 22778606821 in words is "twenty-two billion, seven hundred seventy-eight million, six hundred six thousand, eight hundred twenty-one".