66856075 has 24 divisors (see below), whose sum is σ = 97400016. Its totient is φ = 44880000.

The previous prime is 66856073. The next prime is 66856093. The reversal of 66856075 is 57065866.

It is not a de Polignac number, because 66856075 - 2¹ = 66856073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66856073) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5776 + ... + 12925.

It is an arithmetic number, because the mean of its divisors is an integer number (4058334).

Almost surely, 2^66856075 is an apocalyptic number.

66856075 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66856075 is a deficient number, since it is larger than the sum of its proper divisors (30543941).

66856075 is a wasteful number, since it uses less digits than its factorization.

66856075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18735 (or 18730 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 43.

The square root of 66856075 is about 8176.5564267606. The cubic root of 66856075 is about 405.8637765219.

The spelling of 66856075 in words is "sixty-six million, eight hundred fifty-six thousand, seventy-five".