66216807 has 12 divisors (see below), whose sum is σ = 95990544. Its totient is φ = 43985760.

The previous prime is 66216739. The next prime is 66216809. The reversal of 66216807 is 70861266.

It is a happy number.

It is not a de Polignac number, because 66216807 - 2⁷ = 66216679 is a prime.

It is a super-3 number, since 3×66216807³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66216809) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10563 + ... + 15620.

It is an arithmetic number, because the mean of its divisors is an integer number (7999212).

Almost surely, 2^66216807 is an apocalyptic number.

66216807 is a deficient number, since it is larger than the sum of its proper divisors (29773737).

66216807 is a wasteful number, since it uses less digits than its factorization.

66216807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26470 (or 26467 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 66216807 is about 8137.3710128026. The cubic root of 66216807 is about 404.5660280624.

The spelling of 66216807 in words is "sixty-six million, two hundred sixteen thousand, eight hundred seven".