858090991 has 2 divisors, whose sum is σ = 858090992. Its totient is φ = 858090990.

The previous prime is 858090953. The next prime is 858091001. The reversal of 858090991 is 199090858.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-858090991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (858090391) 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, 429045495 + 429045496.

It is an arithmetic number, because the mean of its divisors is an integer number (429045496).

Almost surely, 2^858090991 is an apocalyptic number.

858090991 is a deficient number, since it is larger than the sum of its proper divisors (1).

858090991 is an equidigital number, since it uses as much as digits as its factorization.

858090991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 49.

The square root of 858090991 is about 29293.1901813374. The cubic root of 858090991 is about 950.2643736972.

The spelling of 858090991 in words is "eight hundred fifty-eight million, ninety thousand, nine hundred ninety-one".