81489571 has 8 divisors (see below), whose sum is σ = 82328400. Its totient is φ = 80655360.

The previous prime is 81489563. The next prime is 81489581. The reversal of 81489571 is 17598418.

It is a happy number.

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 81489571 - 2³ = 81489563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81489581) 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, 42195 + ... + 44083.

It is an arithmetic number, because the mean of its divisors is an integer number (10291050).

Almost surely, 2^81489571 is an apocalyptic number.

81489571 is a deficient number, since it is larger than the sum of its proper divisors (838829).

81489571 is a wasteful number, since it uses less digits than its factorization.

81489571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2309.

The product of its digits is 80640, while the sum is 43.

The square root of 81489571 is about 9027.1574152664. The cubic root of 81489571 is about 433.5448288435.

The spelling of 81489571 in words is "eighty-one million, four hundred eighty-nine thousand, five hundred seventy-one".