84109581 has 12 divisors (see below), whose sum is σ = 121924608. Its totient is φ = 55873224.

The previous prime is 84109577. The next prime is 84109583. The reversal of 84109581 is 18590148.

It is not a de Polignac number, because 84109581 - 2² = 84109577 is a prime.

It is a super-2 number, since 2×84109581² = 14148843231991122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84109583) 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 in 11 ways as a sum of consecutive naturals, for example, 13965 + ... + 19058.

It is an arithmetic number, because the mean of its divisors is an integer number (10160384).

Almost surely, 2^84109581 is an apocalyptic number.

It is an amenable number.

84109581 is a deficient number, since it is larger than the sum of its proper divisors (37815027).

84109581 is a wasteful number, since it uses less digits than its factorization.

84109581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33312 (or 33309 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 84109581 is about 9171.1275751676. The cubic root of 84109581 is about 438.1422725406.

The spelling of 84109581 in words is "eighty-four million, one hundred nine thousand, five hundred eighty-one".