16861386778 has 8 divisors (see below), whose sum is σ = 25528455072. Its totient is φ = 8351901756.

The previous prime is 16861386761. The next prime is 16861386827. The reversal of 16861386778 is 87768316861.

It is a happy number.

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

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, 39395550 + ... + 39395977.

It is an arithmetic number, because the mean of its divisors is an integer number (3191056884).

Almost surely, 2^16861386778 is an apocalyptic number.

16861386778 is a deficient number, since it is larger than the sum of its proper divisors (8667068294).

16861386778 is a wasteful number, since it uses less digits than its factorization.

16861386778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78791636.

The product of its digits is 16257024, while the sum is 61.

The spelling of 16861386778 in words is "sixteen billion, eight hundred sixty-one million, three hundred eighty-six thousand, seven hundred seventy-eight".