84188989 has 2 divisors, whose sum is σ = 84188990. Its totient is φ = 84188988.

The previous prime is 84188987. The next prime is 84188999. The reversal of 84188989 is 98988148.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83722500 + 466489 = 9150^2 + 683^2 .

It is a cyclic number.

It is not a de Polignac number, because 84188989 - 2¹ = 84188987 is a prime.

Together with 84188987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84188987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42094494 + 42094495.

It is an arithmetic number, because the mean of its divisors is an integer number (42094495).

Almost surely, 2^84188989 is an apocalyptic number.

It is an amenable number.

84188989 is a deficient number, since it is larger than the sum of its proper divisors (1).

84188989 is an equidigital number, since it uses as much as digits as its factorization.

84188989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1327104, while the sum is 55.

The square root of 84188989 is about 9175.4557924934. The cubic root of 84188989 is about 438.2801127955.

The spelling of 84188989 in words is "eighty-four million, one hundred eighty-eight thousand, nine hundred eighty-nine".