84213821 has 2 divisors, whose sum is σ = 84213822. Its totient is φ = 84213820.

The previous prime is 84213803. The next prime is 84213839. The reversal of 84213821 is 12831248.

It is a balanced prime because it is at equal distance from previous prime (84213803) and next prime (84213839).

It can be written as a sum of positive squares in only one way, i.e., 70744921 + 13468900 = 8411^2 + 3670^2 .

It is a cyclic number.

It is not a de Polignac number, because 84213821 - 2¹⁰ = 84212797 is a prime.

It is a super-3 number, since 3×84213821³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is equal to p_4900718 and since 84213821 and 4900718 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84213851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42106910 + 42106911.

It is an arithmetic number, because the mean of its divisors is an integer number (42106911).

Almost surely, 2^84213821 is an apocalyptic number.

It is an amenable number.

84213821 is a deficient number, since it is larger than the sum of its proper divisors (1).

84213821 is an equidigital number, since it uses as much as digits as its factorization.

84213821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 29.

The square root of 84213821 is about 9176.8088680107. The cubic root of 84213821 is about 438.3231995935.

The spelling of 84213821 in words is "eighty-four million, two hundred thirteen thousand, eight hundred twenty-one".