20065561457 has 2 divisors, whose sum is σ = 20065561458. Its totient is φ = 20065561456.

The previous prime is 20065561441. The next prime is 20065561493. The reversal of 20065561457 is 75416556002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19397804176 + 667757281 = 139276^2 + 25841^2 .

It is a cyclic number.

It is not a de Polignac number, because 20065561457 - 2⁴ = 20065561441 is a prime.

It is not a weakly prime, because it can be changed into another prime (20065561357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10032780728 + 10032780729.

It is an arithmetic number, because the mean of its divisors is an integer number (10032780729).

Almost surely, 2^20065561457 is an apocalyptic number.

It is an amenable number.

20065561457 is a deficient number, since it is larger than the sum of its proper divisors (1).

20065561457 is an equidigital number, since it uses as much as digits as its factorization.

20065561457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252000, while the sum is 41.

The spelling of 20065561457 in words is "twenty billion, sixty-five million, five hundred sixty-one thousand, four hundred fifty-seven".