991890301 has 2 divisors, whose sum is σ = 991890302. Its totient is φ = 991890300.

The previous prime is 991890271. The next prime is 991890323. The reversal of 991890301 is 103098199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 501312100 + 490578201 = 22390^2 + 22149^2 .

It is a cyclic number.

It is not a de Polignac number, because 991890301 - 2⁷ = 991890173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991890101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495945150 + 495945151.

It is an arithmetic number, because the mean of its divisors is an integer number (495945151).

Almost surely, 2^991890301 is an apocalyptic number.

It is an amenable number.

991890301 is a deficient number, since it is larger than the sum of its proper divisors (1).

991890301 is an equidigital number, since it uses as much as digits as its factorization.

991890301 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 991890301 is about 31494.2899745335. The cubic root of 991890301 is about 997.2894264293.

The spelling of 991890301 in words is "nine hundred ninety-one million, eight hundred ninety thousand, three hundred one".