84911991 has 8 divisors (see below), whose sum is σ = 119875824. Its totient is φ = 53278080.

The previous prime is 84911977. The next prime is 84911993. The reversal of 84911991 is 19911948.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 84911991 - 2⁶ = 84911927 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84911993) 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 in 7 ways as a sum of consecutive naturals, for example, 832420 + ... + 832521.

It is an arithmetic number, because the mean of its divisors is an integer number (14984478).

Almost surely, 2^84911991 is an apocalyptic number.

84911991 is a deficient number, since it is larger than the sum of its proper divisors (34963833).

84911991 is a wasteful number, since it uses less digits than its factorization.

84911991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1664961.

The product of its digits is 23328, while the sum is 42.

The square root of 84911991 is about 9214.7702630071. The cubic root of 84911991 is about 439.5311655639.

The spelling of 84911991 in words is "eighty-four million, nine hundred eleven thousand, nine hundred ninety-one".