66999123 has 8 divisors (see below), whose sum is σ = 99258000. Its totient is φ = 44666064.

The previous prime is 66999113. The next prime is 66999133. The reversal of 66999123 is 32199966.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66999113) and next prime (66999133).

It is not a de Polignac number, because 66999123 - 2⁹ = 66998611 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66999103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1240698 + ... + 1240751.

It is an arithmetic number, because the mean of its divisors is an integer number (12407250).

Almost surely, 2^66999123 is an apocalyptic number.

66999123 is a deficient number, since it is larger than the sum of its proper divisors (32258877).

66999123 is a wasteful number, since it uses less digits than its factorization.

66999123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2481458 (or 2481452 counting only the distinct ones).

The product of its digits is 157464, while the sum is 45.

The square root of 66999123 is about 8185.2992003958. The cubic root of 66999123 is about 406.1530379086.

The spelling of 66999123 in words is "sixty-six million, nine hundred ninety-nine thousand, one hundred twenty-three".