66880784 has 20 divisors (see below), whose sum is σ = 130842816. Its totient is φ = 33114912.

The previous prime is 66880739. The next prime is 66880811. The reversal of 66880784 is 48708866.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18644 + ... + 21939.

Almost surely, 2^66880784 is an apocalyptic number.

It is an amenable number.

66880784 is a deficient number, since it is larger than the sum of its proper divisors (63962032).

66880784 is a wasteful number, since it uses less digits than its factorization.

66880784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40694 (or 40688 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 47.

The square root of 66880784 is about 8178.0672533307. The cubic root of 66880784 is about 405.9137707463.

It can be divided in two parts, 66880 and 784, that multiplied together give a triangular number (52433920 = T₁₀₂₄₀).

The spelling of 66880784 in words is "sixty-six million, eight hundred eighty thousand, seven hundred eighty-four".