66522639991957 has 2 divisors, whose sum is σ = 66522639991958. Its totient is φ = 66522639991956.

The previous prime is 66522639991943. The next prime is 66522639991981. The reversal of 66522639991957 is 75919993622566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66032428569156 + 490211422801 = 8126034^2 + 700151^2 .

It is a cyclic number.

It is not a de Polignac number, because 66522639991957 - 2²⁷ = 66522505774229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66522639991057) 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, 33261319995978 + 33261319995979.

It is an arithmetic number, because the mean of its divisors is an integer number (33261319995979).

Almost surely, 2^{66522639991957} is an apocalyptic number.

It is an amenable number.

66522639991957 is a deficient number, since it is larger than the sum of its proper divisors (1).

66522639991957 is an equidigital number, since it uses as much as digits as its factorization.

66522639991957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2976069600, while the sum is 79.

The spelling of 66522639991957 in words is "sixty-six trillion, five hundred twenty-two billion, six hundred thirty-nine million, nine hundred ninety-one thousand, nine hundred fifty-seven".