66668888890001 has 2 divisors, whose sum is σ = 66668888890002. Its totient is φ = 66668888890000.

The previous prime is 66668888889991. The next prime is 66668888890033. The reversal of 66668888890001 is 10009888886666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65726708054401 + 942180835600 = 8107201^2 + 970660^2 .

It is a cyclic number.

It is not a de Polignac number, because 66668888890001 - 2³⁴ = 66651709020817 is a prime.

It is not a weakly prime, because it can be changed into another prime (66668888890301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33334444445000 + 33334444445001.

It is an arithmetic number, because the mean of its divisors is an integer number (33334444445001).

Almost surely, 2^{66668888890001} is an apocalyptic number.

It is an amenable number.

66668888890001 is a deficient number, since it is larger than the sum of its proper divisors (1).

66668888890001 is an equidigital number, since it uses as much as digits as its factorization.

66668888890001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 382205952, while the sum is 74.

The spelling of 66668888890001 in words is "sixty-six trillion, six hundred sixty-eight billion, eight hundred eighty-eight million, eight hundred ninety thousand, one".