20566851217441 has 2 divisors, whose sum is σ = 20566851217442. Its totient is φ = 20566851217440.

The previous prime is 20566851217399. The next prime is 20566851217447. The reversal of 20566851217441 is 14471215866502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19737840967441 + 829010250000 = 4442729^2 + 910500^2 .

It is a cyclic number.

It is not a de Polignac number, because 20566851217441 - 2¹³ = 20566851209249 is a prime.

It is not a weakly prime, because it can be changed into another prime (20566851217447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10283425608720 + 10283425608721.

It is an arithmetic number, because the mean of its divisors is an integer number (10283425608721).

Almost surely, 2^{20566851217441} is an apocalyptic number.

It is an amenable number.

20566851217441 is a deficient number, since it is larger than the sum of its proper divisors (1).

20566851217441 is an equidigital number, since it uses as much as digits as its factorization.

20566851217441 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3225600, while the sum is 52.

The spelling of 20566851217441 in words is "twenty trillion, five hundred sixty-six billion, eight hundred fifty-one million, two hundred seventeen thousand, four hundred forty-one".