221179913 has 2 divisors, whose sum is σ = 221179914. Its totient is φ = 221179912.

The previous prime is 221179909. The next prime is 221179927. The reversal of 221179913 is 319971122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 205434889 + 15745024 = 14333^2 + 3968^2 .

It is a cyclic number.

It is not a de Polignac number, because 221179913 - 2² = 221179909 is a prime.

It is not a weakly prime, because it can be changed into another prime (221179993) 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, 110589956 + 110589957.

It is an arithmetic number, because the mean of its divisors is an integer number (110589957).

Almost surely, 2^221179913 is an apocalyptic number.

It is an amenable number.

221179913 is a deficient number, since it is larger than the sum of its proper divisors (1).

221179913 is an equidigital number, since it uses as much as digits as its factorization.

221179913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 35.

The square root of 221179913 is about 14872.1186453040. The cubic root of 221179913 is about 604.7583790298.

The spelling of 221179913 in words is "two hundred twenty-one million, one hundred seventy-nine thousand, nine hundred thirteen".