221505983 has 2 divisors, whose sum is σ = 221505984. Its totient is φ = 221505982.

The previous prime is 221505979. The next prime is 221505989. The reversal of 221505983 is 389505122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221505983 - 2² = 221505979 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221505989) 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, 110752991 + 110752992.

It is an arithmetic number, because the mean of its divisors is an integer number (110752992).

Almost surely, 2^221505983 is an apocalyptic number.

221505983 is a deficient number, since it is larger than the sum of its proper divisors (1).

221505983 is an equidigital number, since it uses as much as digits as its factorization.

221505983 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 221505983 is about 14883.0770675959. The cubic root of 221505983 is about 605.0554173675.

The spelling of 221505983 in words is "two hundred twenty-one million, five hundred five thousand, nine hundred eighty-three".