221854998917 has 2 divisors, whose sum is σ = 221854998918. Its totient is φ = 221854998916.

The previous prime is 221854998857. The next prime is 221854998941. The reversal of 221854998917 is 719899458122.

221854998917 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111226252036 + 110628746881 = 333506^2 + 332609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221854998917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221854398917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110927499458 + 110927499459.

It is an arithmetic number, because the mean of its divisors is an integer number (110927499459).

Almost surely, 2^221854998917 is an apocalyptic number.

It is an amenable number.

221854998917 is a deficient number, since it is larger than the sum of its proper divisors (1).

221854998917 is an equidigital number, since it uses as much as digits as its factorization.

221854998917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26127360, while the sum is 65.

The spelling of 221854998917 in words is "two hundred twenty-one billion, eight hundred fifty-four million, nine hundred ninety-eight thousand, nine hundred seventeen".