85428221 has 4 divisors (see below), whose sum is σ = 85801500. Its totient is φ = 85054944.

The previous prime is 85428197. The next prime is 85428241. The reversal of 85428221 is 12282458.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12282458 = 2 ⋅6141229.

It can be written as a sum of positive squares in 2 ways, for example, as 64176121 + 21252100 = 8011^2 + 4610^2 .

It is a cyclic number.

It is not a de Polignac number, because 85428221 - 2¹⁸ = 85166077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85428241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 186296 + ... + 186753.

It is an arithmetic number, because the mean of its divisors is an integer number (21450375).

Almost surely, 2^85428221 is an apocalyptic number.

It is an amenable number.

85428221 is a deficient number, since it is larger than the sum of its proper divisors (373279).

85428221 is a wasteful number, since it uses less digits than its factorization.

85428221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373278.

The product of its digits is 10240, while the sum is 32.

The square root of 85428221 is about 9242.7388256945. The cubic root of 85428221 is about 440.4200894949.

The spelling of 85428221 in words is "eighty-five million, four hundred twenty-eight thousand, two hundred twenty-one".