81404804 has 24 divisors (see below), whose sum is σ = 154320600. Its totient is φ = 37350144.

The previous prime is 81404779. The next prime is 81404819. The reversal of 81404804 is 40840418.

It can be written as a sum of positive squares in 4 ways, for example, as 27352900 + 54051904 = 5230^2 + 7352^2 .

It is a super-2 number, since 2×81404804² = 13253484228556832, which contains 22 as substring.

It is an unprimeable number.

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, 4472 + ... + 13520.

It is an arithmetic number, because the mean of its divisors is an integer number (6430025).

Almost surely, 2^81404804 is an apocalyptic number.

It is an amenable number.

81404804 is a deficient number, since it is larger than the sum of its proper divisors (72915796).

81404804 is a wasteful number, since it uses less digits than its factorization.

81404804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9239 (or 9237 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The square root of 81404804 is about 9022.4610833187. The cubic root of 81404804 is about 433.3944494996.

The spelling of 81404804 in words is "eighty-one million, four hundred four thousand, eight hundred four".