84221821 has 8 divisors (see below), whose sum is σ = 87274880. Its totient is φ = 81218592.

The previous prime is 84221807. The next prime is 84221861. The reversal of 84221821 is 12812248.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84221821 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 84221821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84221861) 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, 9000 + ... + 15793.

It is an arithmetic number, because the mean of its divisors is an integer number (10909360).

Almost surely, 2^84221821 is an apocalyptic number.

It is an amenable number.

84221821 is a deficient number, since it is larger than the sum of its proper divisors (3053059).

84221821 is a wasteful number, since it uses less digits than its factorization.

84221821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24915.

The product of its digits is 2048, while the sum is 28.

The square root of 84221821 is about 9177.2447390271. The cubic root of 84221821 is about 438.3370788457.

The spelling of 84221821 in words is "eighty-four million, two hundred twenty-one thousand, eight hundred twenty-one".