90991193 has 2 divisors, whose sum is σ = 90991194. Its totient is φ = 90991192.

The previous prime is 90991189. The next prime is 90991213. The reversal of 90991193 is 39119909.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48832144 + 42159049 = 6988^2 + 6493^2 .

It is an emirp because it is prime and its reverse (39119909) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90991193 - 2² = 90991189 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 90991193.

It is not a weakly prime, because it can be changed into another prime (90991163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45495596 + 45495597.

It is an arithmetic number, because the mean of its divisors is an integer number (45495597).

Almost surely, 2^90991193 is an apocalyptic number.

It is an amenable number.

90991193 is a deficient number, since it is larger than the sum of its proper divisors (1).

90991193 is an equidigital number, since it uses as much as digits as its factorization.

90991193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19683, while the sum is 41.

The square root of 90991193 is about 9538.9303907723. The cubic root of 90991193 is about 449.7796336674.

The spelling of 90991193 in words is "ninety million, nine hundred ninety-one thousand, one hundred ninety-three".