66142375563221 has 2 divisors, whose sum is σ = 66142375563222. Its totient is φ = 66142375563220.

The previous prime is 66142375563217. The next prime is 66142375563331. The reversal of 66142375563221 is 12236557324166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37188409132900 + 28953966430321 = 6098230^2 + 5380889^2 .

It is a cyclic number.

It is not a de Polignac number, because 66142375563221 - 2² = 66142375563217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66142375563211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33071187781610 + 33071187781611.

It is an arithmetic number, because the mean of its divisors is an integer number (33071187781611).

Almost surely, 2^{66142375563221} is an apocalyptic number.

It is an amenable number.

66142375563221 is a deficient number, since it is larger than the sum of its proper divisors (1).

66142375563221 is an equidigital number, since it uses as much as digits as its factorization.

66142375563221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10886400, while the sum is 53.

The spelling of 66142375563221 in words is "sixty-six trillion, one hundred forty-two billion, three hundred seventy-five million, five hundred sixty-three thousand, two hundred twenty-one".