81204900 has 72 divisors (see below), whose sum is σ = 268524480. Its totient is φ = 18560640.

The previous prime is 81204883. The next prime is 81204911. The reversal of 81204900 is 940218.

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 23 ways as a sum of consecutive naturals, for example, 17235 + ... + 21434.

Almost surely, 2^81204900 is an apocalyptic number.

It is an amenable number.

81204900 is an abundant number, since it is smaller than the sum of its proper divisors (187319580).

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

81204900 is a wasteful number, since it uses less digits than its factorization.

81204900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38693 (or 38686 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 81204900 is about 9011.3761435199. The cubic root of 81204900 is about 433.0393996154.

The spelling of 81204900 in words is "eighty-one million, two hundred four thousand, nine hundred".