84022721 has 4 divisors (see below), whose sum is σ = 88965252. Its totient is φ = 79080192.

The previous prime is 84022691. The next prime is 84022723. The reversal of 84022721 is 12722048.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 78570496 + 5452225 = 8864^2 + 2335^2 .

It is not a de Polignac number, because 84022721 - 2¹⁴ = 84006337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84022723) 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, 2471240 + ... + 2471273.

It is an arithmetic number, because the mean of its divisors is an integer number (22241313).

Almost surely, 2^84022721 is an apocalyptic number.

It is an amenable number.

84022721 is a deficient number, since it is larger than the sum of its proper divisors (4942531).

84022721 is a wasteful number, since it uses less digits than its factorization.

84022721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4942530.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 84022721 is about 9166.3908382744. The cubic root of 84022721 is about 437.9913973554.

Adding to 84022721 its reverse (12722048), we get a palindrome (96744769).

The spelling of 84022721 in words is "eighty-four million, twenty-two thousand, seven hundred twenty-one".