84689021 has 2 divisors, whose sum is σ = 84689022. Its totient is φ = 84689020.

The previous prime is 84688999. The next prime is 84689029. The reversal of 84689021 is 12098648.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65205625 + 19483396 = 8075^2 + 4414^2 .

It is a cyclic number.

It is not a de Polignac number, because 84689021 - 2¹⁸ = 84426877 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 (84689029) 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, 42344510 + 42344511.

It is an arithmetic number, because the mean of its divisors is an integer number (42344511).

Almost surely, 2^84689021 is an apocalyptic number.

It is an amenable number.

84689021 is a deficient number, since it is larger than the sum of its proper divisors (1).

84689021 is an equidigital number, since it uses as much as digits as its factorization.

84689021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 84689021 is about 9202.6637991399. The cubic root of 84689021 is about 439.1461073822.

The spelling of 84689021 in words is "eighty-four million, six hundred eighty-nine thousand, twenty-one".