66690667 has 4 divisors (see below), whose sum is σ = 66785440. Its totient is φ = 66595896.

The previous prime is 66690653. The next prime is 66690713. The reversal of 66690667 is 76609666.

It is a happy number.

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 66690667 - 2¹¹ = 66688619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66699667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46323 + ... + 47740.

It is an arithmetic number, because the mean of its divisors is an integer number (16696360).

Almost surely, 2^66690667 is an apocalyptic number.

66690667 is a deficient number, since it is larger than the sum of its proper divisors (94773).

66690667 is an equidigital number, since it uses as much as digits as its factorization.

66690667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94772.

The product of its (nonzero) digits is 489888, while the sum is 46.

The square root of 66690667 is about 8166.4353912830. The cubic root of 66690667 is about 405.5287854921.

The spelling of 66690667 in words is "sixty-six million, six hundred ninety thousand, six hundred sixty-seven".