221819973 has 24 divisors (see below), whose sum is σ = 310871808. Its totient is φ = 140544000.

The previous prime is 221819957. The next prime is 221819989. The reversal of 221819973 is 379918122.

It is an interprime number because it is at equal distance from previous prime (221819957) and next prime (221819989).

It is not a de Polignac number, because 221819973 - 2⁴ = 221819957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221819903) 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 in 23 ways as a sum of consecutive naturals, for example, 345733 + ... + 346373.

It is an arithmetic number, because the mean of its divisors is an integer number (12952992).

Almost surely, 2^221819973 is an apocalyptic number.

It is an amenable number.

221819973 is a deficient number, since it is larger than the sum of its proper divisors (89051835).

221819973 is an equidigital number, since it uses as much as digits as its factorization.

221819973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797 (or 736 counting only the distinct ones).

The product of its digits is 54432, while the sum is 42.

The square root of 221819973 is about 14893.6218899232. The cubic root of 221819973 is about 605.3411758692.

The spelling of 221819973 in words is "two hundred twenty-one million, eight hundred nineteen thousand, nine hundred seventy-three".