84999891 has 8 divisors (see below), whose sum is σ = 113393104. Its totient is φ = 56636640.

The previous prime is 84999833. The next prime is 84999907. The reversal of 84999891 is 19899948.

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 84999891 - 2⁷ = 84999763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84999091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285 + ... + 13041.

It is an arithmetic number, because the mean of its divisors is an integer number (14174138).

Almost surely, 2^84999891 is an apocalyptic number.

84999891 is a deficient number, since it is larger than the sum of its proper divisors (28393213).

84999891 is a wasteful number, since it uses less digits than its factorization.

84999891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14981.

The product of its digits is 1679616, while the sum is 57.

The square root of 84999891 is about 9219.5385459360. The cubic root of 84999891 is about 439.6827792728.

Adding to 84999891 its sum of digits (57), we get a palindrome (84999948).

The spelling of 84999891 in words is "eighty-four million, nine hundred ninety-nine thousand, eight hundred ninety-one".