84799991 has 2 divisors, whose sum is σ = 84799992. Its totient is φ = 84799990.

The previous prime is 84799969. The next prime is 84799993. The reversal of 84799991 is 19999748.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 84799991 - 2¹⁸ = 84537847 is a prime.

Together with 84799993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84799993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42399995 + 42399996.

It is an arithmetic number, because the mean of its divisors is an integer number (42399996).

Almost surely, 2^84799991 is an apocalyptic number.

84799991 is a deficient number, since it is larger than the sum of its proper divisors (1).

84799991 is an equidigital number, since it uses as much as digits as its factorization.

84799991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1469664, while the sum is 56.

The square root of 84799991 is about 9208.6910579083. The cubic root of 84799991 is about 439.3378314629.

The spelling of 84799991 in words is "eighty-four million, seven hundred ninety-nine thousand, nine hundred ninety-one".