84159991 has 2 divisors, whose sum is σ = 84159992. Its totient is φ = 84159990.

The previous prime is 84159989. The next prime is 84160057. The reversal of 84159991 is 19995148.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 84159991 - 2¹ = 84159989 is a prime.

Together with 84159989, 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 (84159191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42079995 + 42079996.

It is an arithmetic number, because the mean of its divisors is an integer number (42079996).

Almost surely, 2^84159991 is an apocalyptic number.

84159991 is a deficient number, since it is larger than the sum of its proper divisors (1).

84159991 is an equidigital number, since it uses as much as digits as its factorization.

84159991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 46.

The square root of 84159991 is about 9173.8754624204. The cubic root of 84159991 is about 438.2297867123.

The spelling of 84159991 in words is "eighty-four million, one hundred fifty-nine thousand, nine hundred ninety-one".