221001409 has 2 divisors, whose sum is σ = 221001410. Its totient is φ = 221001408.

The previous prime is 221001397. The next prime is 221001421. The reversal of 221001409 is 904100122.

It is a balanced prime because it is at equal distance from previous prime (221001397) and next prime (221001421).

It can be written as a sum of positive squares in only one way, i.e., 192432384 + 28569025 = 13872^2 + 5345^2 .

It is a cyclic number.

It is not a de Polignac number, because 221001409 - 2¹⁵ = 220968641 is a prime.

It is not a weakly prime, because it can be changed into another prime (221001509) 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, 110500704 + 110500705.

It is an arithmetic number, because the mean of its divisors is an integer number (110500705).

Almost surely, 2^221001409 is an apocalyptic number.

It is an amenable number.

221001409 is a deficient number, since it is larger than the sum of its proper divisors (1).

221001409 is an equidigital number, since it uses as much as digits as its factorization.

221001409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 221001409 is about 14866.1161370413. The cubic root of 221001409 is about 604.5956444755.

The spelling of 221001409 in words is "two hundred twenty-one million, one thousand, four hundred nine".