84869821 has 4 divisors (see below), whose sum is σ = 85360572. Its totient is φ = 84379072.

The previous prime is 84869819. The next prime is 84869833. The reversal of 84869821 is 12896848.

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 57684025 + 27185796 = 7595^2 + 5214^2 .

It is a cyclic number.

It is not a de Polignac number, because 84869821 - 2¹ = 84869819 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 (84869861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 245116 + ... + 245461.

It is an arithmetic number, because the mean of its divisors is an integer number (21340143).

Almost surely, 2^84869821 is an apocalyptic number.

It is an amenable number.

84869821 is a deficient number, since it is larger than the sum of its proper divisors (490751).

84869821 is a wasteful number, since it uses less digits than its factorization.

84869821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490750.

The product of its digits is 221184, while the sum is 46.

The square root of 84869821 is about 9212.4818045953. The cubic root of 84869821 is about 439.4583917886.

The spelling of 84869821 in words is "eighty-four million, eight hundred sixty-nine thousand, eight hundred twenty-one".