81471533 has 8 divisors (see below), whose sum is σ = 95714976. Its totient is φ = 68367600.

The previous prime is 81471529. The next prime is 81471553. The reversal of 81471533 is 33517418.

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 81471533 - 2² = 81471529 is a prime.

It is a super-2 number, since 2×81471533² = 13275221378740178, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81471533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81471553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 284723 + ... + 285008.

It is an arithmetic number, because the mean of its divisors is an integer number (11964372).

Almost surely, 2^81471533 is an apocalyptic number.

It is an amenable number.

81471533 is a deficient number, since it is larger than the sum of its proper divisors (14243443).

81471533 is a wasteful number, since it uses less digits than its factorization.

81471533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 569755.

The product of its digits is 10080, while the sum is 32.

The square root of 81471533 is about 9026.1582636247. The cubic root of 81471533 is about 433.5128375976.

The spelling of 81471533 in words is "eighty-one million, four hundred seventy-one thousand, five hundred thirty-three".