221026009 has 2 divisors, whose sum is σ = 221026010. Its totient is φ = 221026008.

The previous prime is 221025983. The next prime is 221026019. The reversal of 221026009 is 900620122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137358400 + 83667609 = 11720^2 + 9147^2 .

It is a cyclic number.

It is not a de Polignac number, because 221026009 - 2¹¹ = 221023961 is a prime.

It is not a weakly prime, because it can be changed into another prime (221026019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110513004 + 110513005.

It is an arithmetic number, because the mean of its divisors is an integer number (110513005).

Almost surely, 2^221026009 is an apocalyptic number.

It is an amenable number.

221026009 is a deficient number, since it is larger than the sum of its proper divisors (1).

221026009 is an equidigital number, since it uses as much as digits as its factorization.

221026009 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 221026009 is about 14866.9434989173. The cubic root of 221026009 is about 604.6180764608.

The spelling of 221026009 in words is "two hundred twenty-one million, twenty-six thousand, nine".