221013409 has 2 divisors, whose sum is σ = 221013410. Its totient is φ = 221013408.

The previous prime is 221013407. The next prime is 221013451. The reversal of 221013409 is 904310122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 177822225 + 43191184 = 13335^2 + 6572^2 .

It is a cyclic number.

It is not a de Polignac number, because 221013409 - 2¹ = 221013407 is a prime.

Together with 221013407, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 221013409.

It is not a weakly prime, because it can be changed into another prime (221013407) 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, 110506704 + 110506705.

It is an arithmetic number, because the mean of its divisors is an integer number (110506705).

Almost surely, 2^221013409 is an apocalyptic number.

It is an amenable number.

221013409 is a deficient number, since it is larger than the sum of its proper divisors (1).

221013409 is an equidigital number, since it uses as much as digits as its factorization.

221013409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 221013409 is about 14866.5197339525. The cubic root of 221013409 is about 604.6065871153.

The spelling of 221013409 in words is "two hundred twenty-one million, thirteen thousand, four hundred nine".