84989821 has 4 divisors (see below), whose sum is σ = 97131232. Its totient is φ = 72848412.

The previous prime is 84989819. The next prime is 84989833. The reversal of 84989821 is 12898948.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 84989821 - 2¹ = 84989819 is a prime.

It is a super-2 number, since 2×84989821² = 14446539347224082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84989881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6070695 + ... + 6070708.

It is an arithmetic number, because the mean of its divisors is an integer number (24282808).

Almost surely, 2^84989821 is an apocalyptic number.

It is an amenable number.

84989821 is a deficient number, since it is larger than the sum of its proper divisors (12141411).

84989821 is a wasteful number, since it uses less digits than its factorization.

84989821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12141410.

The product of its digits is 331776, while the sum is 49.

The square root of 84989821 is about 9218.9924069824. The cubic root of 84989821 is about 439.6654154057.

The spelling of 84989821 in words is "eighty-four million, nine hundred eighty-nine thousand, eight hundred twenty-one".