66245415517373 has 2 divisors, whose sum is σ = 66245415517374. Its totient is φ = 66245415517372.

The previous prime is 66245415517277. The next prime is 66245415517387. The reversal of 66245415517373 is 37371551454266.

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., 63513280908484 + 2732134608889 = 7969522^2 + 1652917^2 .

It is a cyclic number.

It is not a de Polignac number, because 66245415517373 - 2²⁰ = 66245414468797 is a prime.

It is a super-2 number, since 2×66245415517373² (a number of 28 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66245415517873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33122707758686 + 33122707758687.

It is an arithmetic number, because the mean of its divisors is an integer number (33122707758687).

Almost surely, 2^{66245415517373} is an apocalyptic number.

It is an amenable number.

66245415517373 is a deficient number, since it is larger than the sum of its proper divisors (1).

66245415517373 is an equidigital number, since it uses as much as digits as its factorization.

66245415517373 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63504000, while the sum is 59.

The spelling of 66245415517373 in words is "sixty-six trillion, two hundred forty-five billion, four hundred fifteen million, five hundred seventeen thousand, three hundred seventy-three".