16921808243 has 2 divisors, whose sum is σ = 16921808244. Its totient is φ = 16921808242.

The previous prime is 16921808237. The next prime is 16921808251. The reversal of 16921808243 is 34280812961.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16921808243 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16921808194 and 16921808203.

It is not a weakly prime, because it can be changed into another prime (16921808263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8460904121 + 8460904122.

It is an arithmetic number, because the mean of its divisors is an integer number (8460904122).

Almost surely, 2^16921808243 is an apocalyptic number.

16921808243 is a deficient number, since it is larger than the sum of its proper divisors (1).

16921808243 is an equidigital number, since it uses as much as digits as its factorization.

16921808243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 44.

The spelling of 16921808243 in words is "sixteen billion, nine hundred twenty-one million, eight hundred eight thousand, two hundred forty-three".