84986821 has 2 divisors, whose sum is σ = 84986822. Its totient is φ = 84986820.

The previous prime is 84986813. The next prime is 84986831. The reversal of 84986821 is 12868948.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54184321 + 30802500 = 7361^2 + 5550^2 .

It is a cyclic number.

It is not a de Polignac number, because 84986821 - 2³ = 84986813 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84986831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42493410 + 42493411.

It is an arithmetic number, because the mean of its divisors is an integer number (42493411).

Almost surely, 2^84986821 is an apocalyptic number.

It is an amenable number.

84986821 is a deficient number, since it is larger than the sum of its proper divisors (1).

84986821 is an equidigital number, since it uses as much as digits as its factorization.

84986821 is an evil number, because the sum of its binary digits is even.

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

The square root of 84986821 is about 9218.8296979606. The cubic root of 84986821 is about 439.6602421910.

The spelling of 84986821 in words is "eighty-four million, nine hundred eighty-six thousand, eight hundred twenty-one".