81092900 has 144 divisors (see below), whose sum is σ = 215319552. Its totient is φ = 25920000.

The previous prime is 81092899. The next prime is 81092933. The reversal of 81092900 is 929018.

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 47 ways as a sum of consecutive naturals, for example, 802850 + ... + 802950.

Almost surely, 2^81092900 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81092900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107659776).

81092900 is an abundant number, since it is smaller than the sum of its proper divisors (134226652).

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

81092900 is a wasteful number, since it uses less digits than its factorization.

81092900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 81092900 is about 9005.1596321220. The cubic root of 81092900 is about 432.8402214560.

The spelling of 81092900 in words is "eighty-one million, ninety-two thousand, nine hundred".