66281391818 has 8 divisors (see below), whose sum is σ = 99443533440. Its totient is φ = 33133547340.

The previous prime is 66281391797. The next prime is 66281391823. The reversal of 66281391818 is 81819318266.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66281391818.

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, 3562688 + ... + 3581243.

It is an arithmetic number, because the mean of its divisors is an integer number (12430441680).

Almost surely, 2^66281391818 is an apocalyptic number.

66281391818 is a deficient number, since it is larger than the sum of its proper divisors (33162141622).

66281391818 is a wasteful number, since it uses less digits than its factorization.

66281391818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7148572.

The product of its digits is 995328, while the sum is 53.

The spelling of 66281391818 in words is "sixty-six billion, two hundred eighty-one million, three hundred ninety-one thousand, eight hundred eighteen".