66139911 has 12 divisors (see below), whose sum is σ = 101155392. Its totient is φ = 41499456.

The previous prime is 66139907. The next prime is 66139937. The reversal of 66139911 is 11993166.

It is not a de Polignac number, because 66139911 - 2² = 66139907 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66139211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 215991 + ... + 216296.

It is an arithmetic number, because the mean of its divisors is an integer number (8429616).

Almost surely, 2^66139911 is an apocalyptic number.

66139911 is a deficient number, since it is larger than the sum of its proper divisors (35015481).

66139911 is a wasteful number, since it uses less digits than its factorization.

66139911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432310 (or 432307 counting only the distinct ones).

The product of its digits is 8748, while the sum is 36.

The square root of 66139911 is about 8132.6447727661. The cubic root of 66139911 is about 404.4093631071.

The spelling of 66139911 in words is "sixty-six million, one hundred thirty-nine thousand, nine hundred eleven".