81518416 has 20 divisors (see below), whose sum is σ = 180505312. Its totient is φ = 34936416.

The previous prime is 81518401. The next prime is 81518447. The reversal of 81518416 is 61481518.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 363810 + ... + 364033.

Almost surely, 2^81518416 is an apocalyptic number.

It is an amenable number.

81518416 is an abundant number, since it is smaller than the sum of its proper divisors (98986896).

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

81518416 is a wasteful number, since it uses less digits than its factorization.

81518416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727858 (or 727852 counting only the distinct ones).

The product of its digits is 7680, while the sum is 34.

The square root of 81518416 is about 9028.7549529268. The cubic root of 81518416 is about 433.5959770055.

The spelling of 81518416 in words is "eighty-one million, five hundred eighteen thousand, four hundred sixteen".