81778608 has 60 divisors (see below), whose sum is σ = 236770560. Its totient is φ = 26318208.

The previous prime is 81778607. The next prime is 81778691. The reversal of 81778608 is 80687718.

It is not an unprimeable number, because it can be changed into a prime (81778607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5616 + ... + 13967.

It is an arithmetic number, because the mean of its divisors is an integer number (3946176).

Almost surely, 2^81778608 is an apocalyptic number.

It is an amenable number.

81778608 is an abundant number, since it is smaller than the sum of its proper divisors (154991952).

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

81778608 is a wasteful number, since it uses less digits than its factorization.

81778608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19626 (or 19617 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 45.

The square root of 81778608 is about 9043.1525476462. The cubic root of 81778608 is about 434.0568069652.

The spelling of 81778608 in words is "eighty-one million, seven hundred seventy-eight thousand, six hundred eight".