66217828 has 24 divisors (see below), whose sum is σ = 121625280. Its totient is φ = 31484640.

The previous prime is 66217787. The next prime is 66217841. The reversal of 66217828 is 82871266.

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, 14458 + ... + 18478.

It is an arithmetic number, because the mean of its divisors is an integer number (5067720).

Almost surely, 2^66217828 is an apocalyptic number.

It is an amenable number.

66217828 is a deficient number, since it is larger than the sum of its proper divisors (55407452).

66217828 is a wasteful number, since it uses less digits than its factorization.

66217828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4227 (or 4225 counting only the distinct ones).

The product of its digits is 64512, while the sum is 40.

The square root of 66217828 is about 8137.4337478102. The cubic root of 66217828 is about 404.5681073924.

The spelling of 66217828 in words is "sixty-six million, two hundred seventeen thousand, eight hundred twenty-eight".