90249989 has 2 divisors, whose sum is σ = 90249990. Its totient is φ = 90249988.

The previous prime is 90249977. The next prime is 90249997. The reversal of 90249989 is 98994209.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77704225 + 12545764 = 8815^2 + 3542^2 .

It is an emirp because it is prime and its reverse (98994209) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90249989 - 2¹⁶ = 90184453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90249949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45124994 + 45124995.

It is an arithmetic number, because the mean of its divisors is an integer number (45124995).

Almost surely, 2^90249989 is an apocalyptic number.

It is an amenable number.

90249989 is a deficient number, since it is larger than the sum of its proper divisors (1).

90249989 is an equidigital number, since it uses as much as digits as its factorization.

90249989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 50.

The square root of 90249989 is about 9499.9994210526. Note that the first 3 decimals coincide. The cubic root of 90249989 is about 448.5550176994. Note that the first 3 decimals are identical.

The spelling of 90249989 in words is "ninety million, two hundred forty-nine thousand, nine hundred eighty-nine".