66864887 has 8 divisors (see below), whose sum is σ = 70220256. Its totient is φ = 63546912.

The previous prime is 66864869. The next prime is 66864911. The reversal of 66864887 is 78846866.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66864887 - 2¹⁴ = 66848503 is a prime.

It is a super-3 number, since 3×66864887³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66864817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5648 + ... + 12869.

It is an arithmetic number, because the mean of its divisors is an integer number (8777532).

Almost surely, 2^66864887 is an apocalyptic number.

66864887 is a deficient number, since it is larger than the sum of its proper divisors (3355369).

66864887 is a wasteful number, since it uses less digits than its factorization.

66864887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18697.

The product of its digits is 3096576, while the sum is 53.

The square root of 66864887 is about 8177.0952666580. The cubic root of 66864887 is about 405.8816074345.

The spelling of 66864887 in words is "sixty-six million, eight hundred sixty-four thousand, eight hundred eighty-seven".