81804506 has 8 divisors (see below), whose sum is σ = 140236320. Its totient is φ = 35059068.

The previous prime is 81804473. The next prime is 81804509. The reversal of 81804506 is 60540818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81804509) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2921576 + ... + 2921603.

It is an arithmetic number, because the mean of its divisors is an integer number (17529540).

Almost surely, 2^81804506 is an apocalyptic number.

81804506 is a deficient number, since it is larger than the sum of its proper divisors (58431814).

81804506 is a wasteful number, since it uses less digits than its factorization.

81804506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5843188.

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 81804506 is about 9044.5843464473. The cubic root of 81804506 is about 434.1026217858.

The spelling of 81804506 in words is "eighty-one million, eight hundred four thousand, five hundred six".