20978307277 has 2 divisors, whose sum is σ = 20978307278. Its totient is φ = 20978307276.

The previous prime is 20978307253. The next prime is 20978307283. The reversal of 20978307277 is 77270387902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16399619721 + 4578687556 = 128061^2 + 67666^2 .

It is a cyclic number.

It is not a de Polignac number, because 20978307277 - 2³¹ = 18830823629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20978307677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489153638 + 10489153639.

It is an arithmetic number, because the mean of its divisors is an integer number (10489153639).

Almost surely, 2^20978307277 is an apocalyptic number.

It is an amenable number.

20978307277 is a deficient number, since it is larger than the sum of its proper divisors (1).

20978307277 is an equidigital number, since it uses as much as digits as its factorization.

20978307277 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2074464, while the sum is 52.

The spelling of 20978307277 in words is "twenty billion, nine hundred seventy-eight million, three hundred seven thousand, two hundred seventy-seven".