81558241 has 8 divisors (see below), whose sum is σ = 88620800. Its totient is φ = 74772720.

The previous prime is 81558227. The next prime is 81558251. The reversal of 81558241 is 14285518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81558241 - 2⁵ = 81558209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81558197 and 81558206.

It is not an unprimeable number, because it can be changed into a prime (81558221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68646 + ... + 69823.

It is an arithmetic number, because the mean of its divisors is an integer number (11077600).

Almost surely, 2^81558241 is an apocalyptic number.

It is an amenable number.

81558241 is a deficient number, since it is larger than the sum of its proper divisors (7062559).

81558241 is a wasteful number, since it uses less digits than its factorization.

81558241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138519.

The product of its digits is 12800, while the sum is 34.

The square root of 81558241 is about 9030.9601372169. The cubic root of 81558241 is about 433.6665751573. Note that the first 3 decimals are identical.

The spelling of 81558241 in words is "eighty-one million, five hundred fifty-eight thousand, two hundred forty-one".