84309581 has 2 divisors, whose sum is σ = 84309582. Its totient is φ = 84309580.

The previous prime is 84309551. The next prime is 84309629. The reversal of 84309581 is 18590348.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79941481 + 4368100 = 8941^2 + 2090^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84309581 is a prime.

It is a super-2 number, since 2×84309581² = 14216210896791122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84309521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42154790 + 42154791.

It is an arithmetic number, because the mean of its divisors is an integer number (42154791).

Almost surely, 2^84309581 is an apocalyptic number.

It is an amenable number.

84309581 is a deficient number, since it is larger than the sum of its proper divisors (1).

84309581 is an equidigital number, since it uses as much as digits as its factorization.

84309581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 84309581 is about 9182.0248856121. The cubic root of 84309581 is about 438.4892765691.

The spelling of 84309581 in words is "eighty-four million, three hundred nine thousand, five hundred eighty-one".