16863891 has 12 divisors (see below), whose sum is σ = 24715656. Its totient is φ = 10220320.

The previous prime is 16863863. The next prime is 16863901. The reversal of 16863891 is 19836861.

16863891 = 865² + 866² + ... + 886².

It is not a de Polignac number, because 16863891 - 2⁵ = 16863859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16863191) 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, 22866 + ... + 23591.

It is an arithmetic number, because the mean of its divisors is an integer number (2059638).

Almost surely, 2^16863891 is an apocalyptic number.

16863891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

16863891 is a deficient number, since it is larger than the sum of its proper divisors (7851765).

16863891 is a wasteful number, since it uses less digits than its factorization.

16863891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46482 (or 46471 counting only the distinct ones).

The product of its digits is 62208, while the sum is 42.

The square root of 16863891 is about 4106.5668142622. The cubic root of 16863891 is about 256.4400948377.

The spelling of 16863891 in words is "sixteen million, eight hundred sixty-three thousand, eight hundred ninety-one".