81508016 has 20 divisors (see below), whose sum is σ = 158146872. Its totient is φ = 40695936.

The previous prime is 81507989. The next prime is 81508019. The reversal of 81508016 is 61080518.

It is a self number, because there is not a number n which added to its sum of digits gives 81508016.

It is not an unprimeable number, because it can be changed into a prime (81508019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9356 + ... + 15828.

Almost surely, 2^81508016 is an apocalyptic number.

It is an amenable number.

81508016 is a deficient number, since it is larger than the sum of its proper divisors (76638856).

81508016 is a wasteful number, since it uses less digits than its factorization.

81508016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7268 (or 7262 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 29.

The square root of 81508016 is about 9028.1789968963. The cubic root of 81508016 is about 433.5775370416.

The spelling of 81508016 in words is "eighty-one million, five hundred eight thousand, sixteen".