84169021 has 2 divisors, whose sum is σ = 84169022. Its totient is φ = 84169020.

The previous prime is 84169013. The next prime is 84169039. The reversal of 84169021 is 12096148.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78943225 + 5225796 = 8885^2 + 2286^2 .

It is a cyclic number.

It is not a de Polignac number, because 84169021 - 2³ = 84169013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84169051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42084510 + 42084511.

It is an arithmetic number, because the mean of its divisors is an integer number (42084511).

Almost surely, 2^84169021 is an apocalyptic number.

It is an amenable number.

84169021 is a deficient number, since it is larger than the sum of its proper divisors (1).

84169021 is an equidigital number, since it uses as much as digits as its factorization.

84169021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 84169021 is about 9174.3676076338. The cubic root of 84169021 is about 438.2454595335.

The spelling of 84169021 in words is "eighty-four million, one hundred sixty-nine thousand, twenty-one".