90000221 has 2 divisors, whose sum is σ = 90000222. Its totient is φ = 90000220.

The previous prime is 90000217. The next prime is 90000233. The reversal of 90000221 is 12200009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70375321 + 19624900 = 8389^2 + 4430^2 .

It is an emirp because it is prime and its reverse (12200009) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90000221 - 2² = 90000217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 90000196 and 90000205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90000241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45000110 + 45000111.

It is an arithmetic number, because the mean of its divisors is an integer number (45000111).

Almost surely, 2^90000221 is an apocalyptic number.

It is an amenable number.

90000221 is a deficient number, since it is larger than the sum of its proper divisors (1).

90000221 is an equidigital number, since it uses as much as digits as its factorization.

90000221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 90000221 is about 9486.8446282207. The cubic root of 90000221 is about 448.1408414667.

The spelling of 90000221 in words is "ninety million, two hundred twenty-one", and thus it is an aban number.