16865863646 has 24 divisors (see below), whose sum is σ = 26877586680. Its totient is φ = 7915586976.

The previous prime is 16865863643. The next prime is 16865863667. The reversal of 16865863646 is 64636856861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16865863643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 432800 + ... + 470156.

It is an arithmetic number, because the mean of its divisors is an integer number (1119899445).

Almost surely, 2^16865863646 is an apocalyptic number.

16865863646 is a deficient number, since it is larger than the sum of its proper divisors (10011723034).

16865863646 is a wasteful number, since it uses less digits than its factorization.

16865863646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37596 (or 37487 counting only the distinct ones).

The product of its digits is 29859840, while the sum is 59.

The spelling of 16865863646 in words is "sixteen billion, eight hundred sixty-five million, eight hundred sixty-three thousand, six hundred forty-six".