66891184516 has 12 divisors (see below), whose sum is σ = 126064155532. Its totient is φ = 30872854368.

The previous prime is 66891184453. The next prime is 66891184523. The reversal of 66891184516 is 61548119866.

It can be written as a sum of positive squares in 2 ways, for example, as 26586606916 + 40304577600 = 163054^2 + 200760^2 .

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

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 3 ways as a sum of consecutive naturals, for example, 643184415 + ... + 643184518.

Almost surely, 2^66891184516 is an apocalyptic number.

It is an amenable number.

66891184516 is a deficient number, since it is larger than the sum of its proper divisors (59172971016).

66891184516 is a wasteful number, since it uses less digits than its factorization.

66891184516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1286368950 (or 1286368948 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 55.

The spelling of 66891184516 in words is "sixty-six billion, eight hundred ninety-one million, one hundred eighty-four thousand, five hundred sixteen".