66242058721 has 2 divisors, whose sum is σ = 66242058722. Its totient is φ = 66242058720.

The previous prime is 66242058703. The next prime is 66242058731. The reversal of 66242058721 is 12785024266.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50036768721 + 16205290000 = 223689^2 + 127300^2 .

It is a cyclic number.

It is not a de Polignac number, because 66242058721 - 2⁵ = 66242058689 is a prime.

It is not a weakly prime, because it can be changed into another prime (66242058731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33121029360 + 33121029361.

It is an arithmetic number, because the mean of its divisors is an integer number (33121029361).

Almost surely, 2^66242058721 is an apocalyptic number.

It is an amenable number.

66242058721 is a deficient number, since it is larger than the sum of its proper divisors (1).

66242058721 is an equidigital number, since it uses as much as digits as its factorization.

66242058721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 322560, while the sum is 43.

The spelling of 66242058721 in words is "sixty-six billion, two hundred forty-two million, fifty-eight thousand, seven hundred twenty-one".