66685653 has 16 divisors (see below), whose sum is σ = 99907200. Its totient is φ = 43956000.

The previous prime is 66685637. The next prime is 66685693. The reversal of 66685653 is 35658666.

It is not a de Polignac number, because 66685653 - 2⁴ = 66685637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66685599 and 66685608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66685693) 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, 11473 + ... + 16278.

It is an arithmetic number, because the mean of its divisors is an integer number (6244200).

Almost surely, 2^66685653 is an apocalyptic number.

It is an amenable number.

66685653 is a deficient number, since it is larger than the sum of its proper divisors (33221547).

66685653 is a wasteful number, since it uses less digits than its factorization.

66685653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27849 (or 27843 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The square root of 66685653 is about 8166.1283972272. The cubic root of 66685653 is about 405.5186222894.

It can be divided in two parts, 6668 and 5653, that added together give a palindrome (12321).

The spelling of 66685653 in words is "sixty-six million, six hundred eighty-five thousand, six hundred fifty-three".