81543016 has 32 divisors (see below), whose sum is σ = 162586440. Its totient is φ = 38207488.

The previous prime is 81543013. The next prime is 81543023. The reversal of 81543016 is 61034518.

It can be written as a sum of positive squares in 4 ways, for example, as 81540900 + 2116 = 9030^2 + 46^2 .

It is not an unprimeable number, because it can be changed into a prime (81543013) 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, 33786 + ... + 36118.

Almost surely, 2^81543016 is an apocalyptic number.

It is an amenable number.

81543016 is a deficient number, since it is larger than the sum of its proper divisors (81043424).

81543016 is a wasteful number, since it uses less digits than its factorization.

81543016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2613 (or 2609 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 81543016 is about 9030.1171642454. The cubic root of 81543016 is about 433.6395883708.

The spelling of 81543016 in words is "eighty-one million, five hundred forty-three thousand, sixteen".