66688023 has 16 divisors (see below), whose sum is σ = 94474080. Its totient is φ = 41763456.

The previous prime is 66688021. The next prime is 66688031. The reversal of 66688023 is 32088666.

It is not a de Polignac number, because 66688023 - 2¹ = 66688021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66688021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7140 + ... + 13577.

It is an arithmetic number, because the mean of its divisors is an integer number (5904630).

Almost surely, 2^66688023 is an apocalyptic number.

66688023 is a deficient number, since it is larger than the sum of its proper divisors (27786057).

66688023 is a wasteful number, since it uses less digits than its factorization.

66688023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20786.

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 66688023 is about 8166.2735075431. The cubic root of 66688023 is about 405.5234262600.

The spelling of 66688023 in words is "sixty-six million, six hundred eighty-eight thousand, twenty-three".