66167056765081 has 2 divisors, whose sum is σ = 66167056765082. Its totient is φ = 66167056765080.

The previous prime is 66167056765067. The next prime is 66167056765127. The reversal of 66167056765081 is 18056765076166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37857378537225 + 28309678227856 = 6152835^2 + 5320684^2 .

It is a cyclic number.

It is not a de Polignac number, because 66167056765081 - 2⁵ = 66167056765049 is a prime.

It is a super-2 number, since 2×66167056765081² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66167056768081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33083528382540 + 33083528382541.

It is an arithmetic number, because the mean of its divisors is an integer number (33083528382541).

Almost surely, 2^{66167056765081} is an apocalyptic number.

It is an amenable number.

66167056765081 is a deficient number, since it is larger than the sum of its proper divisors (1).

66167056765081 is an equidigital number, since it uses as much as digits as its factorization.

66167056765081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 76204800, while the sum is 64.

The spelling of 66167056765081 in words is "sixty-six trillion, one hundred sixty-seven billion, fifty-six million, seven hundred sixty-five thousand, eighty-one".