66872215 has 4 divisors (see below), whose sum is σ = 80246664. Its totient is φ = 53497768.

The previous prime is 66872147. The next prime is 66872227. The reversal of 66872215 is 51227866.

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 66872215 - 2¹³ = 66864023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6687217 + ... + 6687226.

It is an arithmetic number, because the mean of its divisors is an integer number (20061666).

Almost surely, 2^66872215 is an apocalyptic number.

66872215 is a deficient number, since it is larger than the sum of its proper divisors (13374449).

66872215 is a wasteful number, since it uses less digits than its factorization.

66872215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13374448.

The product of its digits is 40320, while the sum is 37.

The square root of 66872215 is about 8177.5433352566. The cubic root of 66872215 is about 405.8964343085.

The spelling of 66872215 in words is "sixty-six million, eight hundred seventy-two thousand, two hundred fifteen".