16645997866 has 16 divisors (see below), whose sum is σ = 25168622688. Its totient is φ = 8256502800.

The previous prime is 16645997861. The next prime is 16645997873. The reversal of 16645997866 is 66879954661.

It is not an unprimeable number, because it can be changed into a prime (16645997861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 842521 + ... + 862051.

It is an arithmetic number, because the mean of its divisors is an integer number (1573038918).

Almost surely, 2^16645997866 is an apocalyptic number.

16645997866 is a deficient number, since it is larger than the sum of its proper divisors (8522624822).

16645997866 is a wasteful number, since it uses less digits than its factorization.

16645997866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22917.

The product of its digits is 117573120, while the sum is 67.

The spelling of 16645997866 in words is "sixteen billion, six hundred forty-five million, nine hundred ninety-seven thousand, eight hundred sixty-six".