90190561 has 2 divisors, whose sum is σ = 90190562. Its totient is φ = 90190560.

The previous prime is 90190547. The next prime is 90190579. The reversal of 90190561 is 16509109.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87235600 + 2954961 = 9340^2 + 1719^2 .

It is a cyclic number.

It is not a de Polignac number, because 90190561 - 2¹¹ = 90188513 is a prime.

It is not a weakly prime, because it can be changed into another prime (90190591) 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, 45095280 + 45095281.

It is an arithmetic number, because the mean of its divisors is an integer number (45095281).

Almost surely, 2^90190561 is an apocalyptic number.

It is an amenable number.

90190561 is a deficient number, since it is larger than the sum of its proper divisors (1).

90190561 is an equidigital number, since it uses as much as digits as its factorization.

90190561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 90190561 is about 9496.8711163204. The cubic root of 90190561 is about 448.4565409350.

The spelling of 90190561 in words is "ninety million, one hundred ninety thousand, five hundred sixty-one".