16221473857 has 2 divisors, whose sum is σ = 16221473858. Its totient is φ = 16221473856.

The previous prime is 16221473803. The next prime is 16221473867. The reversal of 16221473857 is 75837412261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15753011121 + 468462736 = 125511^2 + 21644^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16221473857 is a prime.

It is not a weakly prime, because it can be changed into another prime (16221473867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8110736928 + 8110736929.

It is an arithmetic number, because the mean of its divisors is an integer number (8110736929).

Almost surely, 2^16221473857 is an apocalyptic number.

It is an amenable number.

16221473857 is a deficient number, since it is larger than the sum of its proper divisors (1).

16221473857 is an equidigital number, since it uses as much as digits as its factorization.

16221473857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 564480, while the sum is 46.

The spelling of 16221473857 in words is "sixteen billion, two hundred twenty-one million, four hundred seventy-three thousand, eight hundred fifty-seven".