66212665 has 8 divisors (see below), whose sum is σ = 80461440. Its totient is φ = 52299312.

The previous prime is 66212651. The next prime is 66212681. The reversal of 66212665 is 56621266.

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 66212665 - 2⁷ = 66212537 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66212665.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83419 + ... + 84208.

It is an arithmetic number, because the mean of its divisors is an integer number (10057680).

Almost surely, 2^66212665 is an apocalyptic number.

It is an amenable number.

66212665 is a deficient number, since it is larger than the sum of its proper divisors (14248775).

66212665 is a wasteful number, since it uses less digits than its factorization.

66212665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167711.

The product of its digits is 25920, while the sum is 34.

The square root of 66212665 is about 8137.1165040203. The cubic root of 66212665 is about 404.5575924023.

The spelling of 66212665 in words is "sixty-six million, two hundred twelve thousand, six hundred sixty-five".