20355266644649 has 2 divisors, whose sum is σ = 20355266644650. Its totient is φ = 20355266644648.

The previous prime is 20355266644481. The next prime is 20355266644697. The reversal of 20355266644649 is 94644666255302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15994240518400 + 4361026126249 = 3999280^2 + 2088307^2 .

It is a cyclic number.

It is not a de Polignac number, because 20355266644649 - 2³² = 20350971677353 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20355266644591 and 20355266644600.

It is not a weakly prime, because it can be changed into another prime (20355266344649) 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, 10177633322324 + 10177633322325.

It is an arithmetic number, because the mean of its divisors is an integer number (10177633322325).

Almost surely, 2^{20355266644649} is an apocalyptic number.

It is an amenable number.

20355266644649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20355266644649 is an equidigital number, since it uses as much as digits as its factorization.

20355266644649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 223948800, while the sum is 62.

The spelling of 20355266644649 in words is "twenty trillion, three hundred fifty-five billion, two hundred sixty-six million, six hundred forty-four thousand, six hundred forty-nine".