66666536 has 16 divisors (see below), whose sum is σ = 125099700. Its totient is φ = 33306624.

The previous prime is 66666517. The next prime is 66666557. The reversal of 66666536 is 63566666.

It can be written as a sum of positive squares in 2 ways, for example, as 66422500 + 244036 = 8150^2 + 494^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10856 + ... + 15848.

Almost surely, 2^66666536 is an apocalyptic number.

It is an amenable number.

66666536 is a deficient number, since it is larger than the sum of its proper divisors (58433164).

66666536 is a wasteful number, since it uses less digits than its factorization.

66666536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6668 (or 6664 counting only the distinct ones).

The product of its digits is 699840, while the sum is 44.

The square root of 66666536 is about 8164.9578076068. The cubic root of 66666536 is about 405.4798681244.

Adding to 66666536 its product of digits (699840), we get a palindrome (67366376).

The spelling of 66666536 in words is "sixty-six million, six hundred sixty-six thousand, five hundred thirty-six".