66784394986 has 4 divisors (see below), whose sum is σ = 100176592482. Its totient is φ = 33392197492.

The previous prime is 66784394977. The next prime is 66784394993. The reversal of 66784394986 is 68949348766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 59502332761 + 7282062225 = 243931^2 + 85335^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16696098745 + ... + 16696098748.

Almost surely, 2^66784394986 is an apocalyptic number.

66784394986 is a deficient number, since it is larger than the sum of its proper divisors (33392197496).

66784394986 is a wasteful number, since it uses less digits than its factorization.

66784394986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33392197495.

The product of its digits is 376233984, while the sum is 70.

The spelling of 66784394986 in words is "sixty-six billion, seven hundred eighty-four million, three hundred ninety-four thousand, nine hundred eighty-six".