81004002 has 16 divisors (see below), whose sum is σ = 165776160. Its totient is φ = 26373312.

The previous prime is 81003977. The next prime is 81004003. The reversal of 81004002 is 20040018.

It is not an unprimeable number, because it can be changed into a prime (81004003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156727 + ... + 157242.

It is an arithmetic number, because the mean of its divisors is an integer number (10361010).

Almost surely, 2^81004002 is an apocalyptic number.

81004002 is an abundant number, since it is smaller than the sum of its proper divisors (84772158).

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

81004002 is a wasteful number, since it uses less digits than its factorization.

81004002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314017.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 81004002 is about 9000.2223305872. Note that the first 3 decimals coincide. The cubic root of 81004002 is about 432.6819967561.

The spelling of 81004002 in words is "eighty-one million, four thousand, two".