20522020721 has 2 divisors, whose sum is σ = 20522020722. Its totient is φ = 20522020720.

The previous prime is 20522020667. The next prime is 20522020763. The reversal of 20522020721 is 12702022502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20513400625 + 8620096 = 143225^2 + 2936^2 .

It is a cyclic number.

It is not a de Polignac number, because 20522020721 - 2²⁶ = 20454911857 is a prime.

It is not a weakly prime, because it can be changed into another prime (20522020121) 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, 10261010360 + 10261010361.

It is an arithmetic number, because the mean of its divisors is an integer number (10261010361).

Almost surely, 2^20522020721 is an apocalyptic number.

It is an amenable number.

20522020721 is a deficient number, since it is larger than the sum of its proper divisors (1).

20522020721 is an equidigital number, since it uses as much as digits as its factorization.

20522020721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 23.

The spelling of 20522020721 in words is "twenty billion, five hundred twenty-two million, twenty thousand, seven hundred twenty-one".