66839699 has 4 divisors (see below), whose sum is σ = 70771464. Its totient is φ = 62907936.

The previous prime is 66839683. The next prime is 66839741. The reversal of 66839699 is 99693866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66839699 - 2⁴ = 66839683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66839099) 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 3 ways as a sum of consecutive naturals, for example, 1965857 + ... + 1965890.

It is an arithmetic number, because the mean of its divisors is an integer number (17692866).

Almost surely, 2^66839699 is an apocalyptic number.

66839699 is a deficient number, since it is larger than the sum of its proper divisors (3931765).

66839699 is a wasteful number, since it uses less digits than its factorization.

66839699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3931764.

The product of its digits is 3779136, while the sum is 56.

The square root of 66839699 is about 8175.5549658723. The cubic root of 66839699 is about 405.8306358390.

The spelling of 66839699 in words is "sixty-six million, eight hundred thirty-nine thousand, six hundred ninety-nine".