20320779649 has 2 divisors, whose sum is σ = 20320779650. Its totient is φ = 20320779648.

The previous prime is 20320779599. The next prime is 20320779659. The reversal of 20320779649 is 94697702302.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19920499600 + 400280049 = 141140^2 + 20007^2 .

It is a cyclic number.

It is not a de Polignac number, because 20320779649 - 2¹⁵ = 20320746881 is a prime.

It is not a weakly prime, because it can be changed into another prime (20320779659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10160389824 + 10160389825.

It is an arithmetic number, because the mean of its divisors is an integer number (10160389825).

Almost surely, 2^20320779649 is an apocalyptic number.

It is an amenable number.

20320779649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20320779649 is an equidigital number, since it uses as much as digits as its factorization.

20320779649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1143072, while the sum is 49.

The spelling of 20320779649 in words is "twenty billion, three hundred twenty million, seven hundred seventy-nine thousand, six hundred forty-nine".