66602689 has 4 divisors (see below), whose sum is σ = 66683860. Its totient is φ = 66521520.

The previous prime is 66602671. The next prime is 66602693. The reversal of 66602689 is 98620666.

It is a happy number.

66602689 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 49463089 + 17139600 = 7033^2 + 4140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66602689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66602639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39342 + ... + 40999.

It is an arithmetic number, because the mean of its divisors is an integer number (16670965).

Almost surely, 2^66602689 is an apocalyptic number.

It is an amenable number.

66602689 is a deficient number, since it is larger than the sum of its proper divisors (81171).

66602689 is an equidigital number, since it uses as much as digits as its factorization.

66602689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81170.

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 66602689 is about 8161.0470529216. The cubic root of 66602689 is about 405.3503831599.

The spelling of 66602689 in words is "sixty-six million, six hundred two thousand, six hundred eighty-nine".