66729866 has 12 divisors (see below), whose sum is σ = 116436978. Its totient is φ = 28598472.

The previous prime is 66729863. The next prime is 66729893. The reversal of 66729866 is 66892766.

It can be written as a sum of positive squares in only one way, i.e., 64464841 + 2265025 = 8029^2 + 1505^2 .

It is not an unprimeable number, because it can be changed into a prime (66729863) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 340361 + ... + 340556.

Almost surely, 2^66729866 is an apocalyptic number.

66729866 is a deficient number, since it is larger than the sum of its proper divisors (49707112).

66729866 is a wasteful number, since it uses less digits than its factorization.

66729866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680933 (or 680926 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 50.

The square root of 66729866 is about 8168.8350454639. The cubic root of 66729866 is about 405.6082229412.

The spelling of 66729866 in words is "sixty-six million, seven hundred twenty-nine thousand, eight hundred sixty-six".