16856870517 has 6 divisors (see below), whose sum is σ = 24348812982. Its totient is φ = 11237913672.

The previous prime is 16856870477. The next prime is 16856870539. The reversal of 16856870517 is 71507865861.

16856870517 is a `hidden beast` number, since 1 + 6 + 8 + 56 + 8 + 70 + 517 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13663038321 + 3193832196 = 116889^2 + 56514^2 .

It is not a de Polignac number, because 16856870517 - 2¹² = 16856866421 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16856870417) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 936492798 + ... + 936492815.

It is an arithmetic number, because the mean of its divisors is an integer number (4058135497).

Almost surely, 2^16856870517 is an apocalyptic number.

It is an amenable number.

16856870517 is a deficient number, since it is larger than the sum of its proper divisors (7491942465).

16856870517 is a wasteful number, since it uses less digits than its factorization.

16856870517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1872985619 (or 1872985616 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 54.

The spelling of 16856870517 in words is "sixteen billion, eight hundred fifty-six million, eight hundred seventy thousand, five hundred seventeen".