81471516 has 72 divisors (see below), whose sum is σ = 223082496. Its totient is φ = 23073120.

The previous prime is 81471437. The next prime is 81471529. The reversal of 81471516 is 61517418.

It is a happy number.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74131 + ... + 75221.

It is an arithmetic number, because the mean of its divisors is an integer number (3098368).

Almost surely, 2^81471516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81471516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111541248).

81471516 is an abundant number, since it is smaller than the sum of its proper divisors (141610980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81471516 is a wasteful number, since it uses less digits than its factorization.

81471516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239 (or 1230 counting only the distinct ones).

The product of its digits is 6720, while the sum is 33.

The square root of 81471516 is about 9026.1573219172. The cubic root of 81471516 is about 433.5128074451.

The spelling of 81471516 in words is "eighty-one million, four hundred seventy-one thousand, five hundred sixteen".