81580811 has 8 divisors (see below), whose sum is σ = 88418064. Its totient is φ = 74823840.

The previous prime is 81580801. The next prime is 81580823. The reversal of 81580811 is 11808518.

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

It is a de Polignac number, because none of the positive numbers 2^k-81580811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81580801) 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, 17945 + ... + 22026.

It is an arithmetic number, because the mean of its divisors is an integer number (11052258).

Almost surely, 2^81580811 is an apocalyptic number.

81580811 is a deficient number, since it is larger than the sum of its proper divisors (6837253).

81580811 is a wasteful number, since it uses less digits than its factorization.

81580811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40141.

The product of its (nonzero) digits is 2560, while the sum is 32.

The square root of 81580811 is about 9032.2096410568. The cubic root of 81580811 is about 433.7065750058.

The spelling of 81580811 in words is "eighty-one million, five hundred eighty thousand, eight hundred eleven".