66515772563 has 2 divisors, whose sum is σ = 66515772564. Its totient is φ = 66515772562.

The previous prime is 66515772523. The next prime is 66515772577. The reversal of 66515772563 is 36527751566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66515772563 - 2³⁰ = 65442030739 is a prime.

It is not a weakly prime, because it can be changed into another prime (66515772523) 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, 33257886281 + 33257886282.

It is an arithmetic number, because the mean of its divisors is an integer number (33257886282).

Almost surely, 2^66515772563 is an apocalyptic number.

66515772563 is a deficient number, since it is larger than the sum of its proper divisors (1).

66515772563 is an equidigital number, since it uses as much as digits as its factorization.

66515772563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7938000, while the sum is 53.

The spelling of 66515772563 in words is "sixty-six billion, five hundred fifteen million, seven hundred seventy-two thousand, five hundred sixty-three".