90018121 has 2 divisors, whose sum is σ = 90018122. Its totient is φ = 90018120.

The previous prime is 90018119. The next prime is 90018161. The reversal of 90018121 is 12181009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79905721 + 10112400 = 8939^2 + 3180^2 .

It is a cyclic number.

It is not a de Polignac number, because 90018121 - 2¹ = 90018119 is a prime.

Together with 90018119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 90018092 and 90018101.

It is not a weakly prime, because it can be changed into another prime (90018161) 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, 45009060 + 45009061.

It is an arithmetic number, because the mean of its divisors is an integer number (45009061).

Almost surely, 2^90018121 is an apocalyptic number.

It is an amenable number.

90018121 is a deficient number, since it is larger than the sum of its proper divisors (1).

90018121 is an equidigital number, since it uses as much as digits as its factorization.

90018121 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 22.

The square root of 90018121 is about 9487.7879929939. The cubic root of 90018121 is about 448.1705495023.

The spelling of 90018121 in words is "ninety million, eighteen thousand, one hundred twenty-one".