81584069 has 12 divisors (see below), whose sum is σ = 95125248. Its totient is φ = 69766200.

The previous prime is 81584053. The next prime is 81584077. The reversal of 81584069 is 96048518.

It is not a de Polignac number, because 81584069 - 2⁴ = 81584053 is a prime.

It is a super-2 number, since 2×81584069² = 13311920629193522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81584039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22364 + ... + 25754.

It is an arithmetic number, because the mean of its divisors is an integer number (7927104).

Almost surely, 2^81584069 is an apocalyptic number.

It is an amenable number.

81584069 is a deficient number, since it is larger than the sum of its proper divisors (13541179).

81584069 is a wasteful number, since it uses less digits than its factorization.

81584069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3896 (or 3889 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 81584069 is about 9032.3899937946. The cubic root of 81584069 is about 433.7123484109.

The spelling of 81584069 in words is "eighty-one million, five hundred eighty-four thousand, sixty-nine".