81002008 has 32 divisors (see below), whose sum is σ = 166008960. Its totient is φ = 36887040.

The previous prime is 81002003. The next prime is 81002023. The reversal of 81002008 is 80020018.

It is a happy number.

It is a super-3 number, since 3×81002008³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81002003) 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, 5391 + ... + 13822.

It is an arithmetic number, because the mean of its divisors is an integer number (5187780).

Almost surely, 2^81002008 is an apocalyptic number.

It is an amenable number.

81002008 is an abundant number, since it is smaller than the sum of its proper divisors (85006952).

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

81002008 is a wasteful number, since it uses less digits than its factorization.

81002008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19267 (or 19263 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 81002008 is about 9000.1115548642. Note that the first 3 decimals coincide. The cubic root of 81002008 is about 432.6784464172.

The spelling of 81002008 in words is "eighty-one million, two thousand, eight".