66669697 has 4 divisors (see below), whose sum is σ = 66686400. Its totient is φ = 66652996.

The previous prime is 66669683. The next prime is 66669719. The reversal of 66669697 is 79696666.

It is a happy number.

66669697 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66669697 - 2⁷ = 66669569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66669997) 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, 1548 + ... + 11650.

It is an arithmetic number, because the mean of its divisors is an integer number (16671600).

Almost surely, 2^66669697 is an apocalyptic number.

It is an amenable number.

66669697 is a deficient number, since it is larger than the sum of its proper divisors (16703).

66669697 is a wasteful number, since it uses less digits than its factorization.

66669697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16702.

The product of its digits is 4408992, while the sum is 55.

The square root of 66669697 is about 8165.1513764290. The cubic root of 66669697 is about 405.4862766450.

The spelling of 66669697 in words is "sixty-six million, six hundred sixty-nine thousand, six hundred ninety-seven".