66518785 has 8 divisors (see below), whose sum is σ = 81980136. Its totient is φ = 51776640.

The previous prime is 66518761. The next prime is 66518819. The reversal of 66518785 is 58781566.

It can be written as a sum of positive squares in 4 ways, for example, as 8133904 + 58384881 = 2852^2 + 7641^2 .

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

It is not a de Polignac number, because 66518785 - 2²¹ = 64421633 is a prime.

It is a Duffinian 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 7 ways as a sum of consecutive naturals, for example, 179596 + ... + 179965.

It is an arithmetic number, because the mean of its divisors is an integer number (10247517).

Almost surely, 2^66518785 is an apocalyptic number.

It is an amenable number.

66518785 is a deficient number, since it is larger than the sum of its proper divisors (15461351).

66518785 is a wasteful number, since it uses less digits than its factorization.

66518785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359603.

The product of its digits is 403200, while the sum is 46.

The square root of 66518785 is about 8155.9049160715. The cubic root of 66518785 is about 405.1800956893.

The spelling of 66518785 in words is "sixty-six million, five hundred eighteen thousand, seven hundred eighty-five".