90819217 has 2 divisors, whose sum is σ = 90819218. Its totient is φ = 90819216.

The previous prime is 90819191. The next prime is 90819229. The reversal of 90819217 is 71291809.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82519056 + 8300161 = 9084^2 + 2881^2 .

It is a cyclic number.

It is not a de Polignac number, because 90819217 - 2⁷ = 90819089 is a prime.

It is not a weakly prime, because it can be changed into another prime (90819277) 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, 45409608 + 45409609.

It is an arithmetic number, because the mean of its divisors is an integer number (45409609).

Almost surely, 2^90819217 is an apocalyptic number.

It is an amenable number.

90819217 is a deficient number, since it is larger than the sum of its proper divisors (1).

90819217 is an equidigital number, since it uses as much as digits as its factorization.

90819217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 90819217 is about 9529.9116994860. The cubic root of 90819217 is about 449.4960894289.

It can be divided in two parts, 908192 and 17, that added together give a square (908209 = 953²).

The spelling of 90819217 in words is "ninety million, eight hundred nineteen thousand, two hundred seventeen".