90123221 has 2 divisors, whose sum is σ = 90123222. Its totient is φ = 90123220.

The previous prime is 90123197. The next prime is 90123247. The reversal of 90123221 is 12232109.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47416996 + 42706225 = 6886^2 + 6535^2 .

It is a cyclic number.

It is not a de Polignac number, because 90123221 - 2¹⁸ = 89861077 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 90123193 and 90123202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90123281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45061610 + 45061611.

It is an arithmetic number, because the mean of its divisors is an integer number (45061611).

Almost surely, 2^90123221 is an apocalyptic number.

It is an amenable number.

90123221 is a deficient number, since it is larger than the sum of its proper divisors (1).

90123221 is an equidigital number, since it uses as much as digits as its factorization.

90123221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 90123221 is about 9493.3250760732. The cubic root of 90123221 is about 448.3449010833.

The spelling of 90123221 in words is "ninety million, one hundred twenty-three thousand, two hundred twenty-one".