16851333491 has 4 divisors (see below), whose sum is σ = 17738245800. Its totient is φ = 15964421184.

The previous prime is 16851333481. The next prime is 16851333533. The reversal of 16851333491 is 19433315861.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16851333491 - 2¹⁴ = 16851317107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16851333451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 443456126 + ... + 443456163.

It is an arithmetic number, because the mean of its divisors is an integer number (4434561450).

Almost surely, 2^16851333491 is an apocalyptic number.

16851333491 is a deficient number, since it is larger than the sum of its proper divisors (886912309).

16851333491 is an equidigital number, since it uses as much as digits as its factorization.

16851333491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886912308.

The product of its digits is 233280, while the sum is 44.

The spelling of 16851333491 in words is "sixteen billion, eight hundred fifty-one million, three hundred thirty-three thousand, four hundred ninety-one".