221479913 has 2 divisors, whose sum is σ = 221479914. Its totient is φ = 221479912.

The previous prime is 221479889. The next prime is 221479967. The reversal of 221479913 is 319974122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118091689 + 103388224 = 10867^2 + 10168^2 .

It is a cyclic number.

It is not a de Polignac number, because 221479913 - 2⁶ = 221479849 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (221473913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110739956 + 110739957.

It is an arithmetic number, because the mean of its divisors is an integer number (110739957).

Almost surely, 2^221479913 is an apocalyptic number.

It is an amenable number.

221479913 is a deficient number, since it is larger than the sum of its proper divisors (1).

221479913 is an equidigital number, since it uses as much as digits as its factorization.

221479913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 38.

The square root of 221479913 is about 14882.2012148741. The cubic root of 221479913 is about 605.0316792373.

The spelling of 221479913 in words is "two hundred twenty-one million, four hundred seventy-nine thousand, nine hundred thirteen".