16781206685 has 16 divisors (see below), whose sum is σ = 21331629936. Its totient is φ = 12629557248.

The previous prime is 16781206667. The next prime is 16781206693. The reversal of 16781206685 is 58660218761.

It can be written as a sum of positive squares in 8 ways, for example, as 894368836 + 15886837849 = 29906^2 + 126043^2 .

It is a cyclic number.

It is not a de Polignac number, because 16781206685 - 2¹⁴ = 16781190301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149777 + ... + 236633.

It is an arithmetic number, because the mean of its divisors is an integer number (1333226871).

Almost surely, 2^16781206685 is an apocalyptic number.

It is an amenable number.

16781206685 is a deficient number, since it is larger than the sum of its proper divisors (4550423251).

16781206685 is a wasteful number, since it uses less digits than its factorization.

16781206685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89152.

The product of its (nonzero) digits is 967680, while the sum is 50.

The spelling of 16781206685 in words is "sixteen billion, seven hundred eighty-one million, two hundred six thousand, six hundred eighty-five".