66042139 has 2 divisors, whose sum is σ = 66042140. Its totient is φ = 66042138.

The previous prime is 66042133. The next prime is 66042167. The reversal of 66042139 is 93124066.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66042139 - 2⁵ = 66042107 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66042139.

It is not a weakly prime, because it can be changed into another prime (66042133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33021069 + 33021070.

It is an arithmetic number, because the mean of its divisors is an integer number (33021070).

Almost surely, 2^66042139 is an apocalyptic number.

66042139 is a deficient number, since it is larger than the sum of its proper divisors (1).

66042139 is an equidigital number, since it uses as much as digits as its factorization.

66042139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 66042139 is about 8126.6314669733. The cubic root of 66042139 is about 404.2099907408.

The spelling of 66042139 in words is "sixty-six million, forty-two thousand, one hundred thirty-nine".