81280404 has 36 divisors (see below), whose sum is σ = 216274240. Its totient is φ = 25667280.

The previous prime is 81280373. The next prime is 81280421. The reversal of 81280404 is 40408218.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58732 + ... + 60099.

Almost surely, 2^81280404 is an apocalyptic number.

It is an amenable number.

81280404 is an abundant number, since it is smaller than the sum of its proper divisors (134993836).

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

81280404 is a wasteful number, since it uses less digits than its factorization.

81280404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118860 (or 118855 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 81280404 is about 9015.5645413917. The cubic root of 81280404 is about 433.1735708229.

The spelling of 81280404 in words is "eighty-one million, two hundred eighty thousand, four hundred four".