84865821 has 4 divisors (see below), whose sum is σ = 113154432. Its totient is φ = 56577212.

The previous prime is 84865813. The next prime is 84865841. The reversal of 84865821 is 12856848.

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 a cyclic number.

It is not a de Polignac number, because 84865821 - 2³ = 84865813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84865841) 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, 14144301 + ... + 14144306.

It is an arithmetic number, because the mean of its divisors is an integer number (28288608).

Almost surely, 2^84865821 is an apocalyptic number.

It is an amenable number.

84865821 is a deficient number, since it is larger than the sum of its proper divisors (28288611).

84865821 is a wasteful number, since it uses less digits than its factorization.

84865821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28288610.

The product of its digits is 122880, while the sum is 42.

The square root of 84865821 is about 9212.2647052720. The cubic root of 84865821 is about 439.4514876415.

The spelling of 84865821 in words is "eighty-four million, eight hundred sixty-five thousand, eight hundred twenty-one".