81361104 has 80 divisors (see below), whose sum is σ = 230651904. Its totient is φ = 24508800.

The previous prime is 81361079. The next prime is 81361123. The reversal of 81361104 is 40116318.

It is a Harshad number since it is a multiple of its sum of digits (24).

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 15 ways as a sum of consecutive naturals, for example, 117399 + ... + 118089.

Almost surely, 2^81361104 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 81361104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115325952).

81361104 is an abundant number, since it is smaller than the sum of its proper divisors (149290800).

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

81361104 is a wasteful number, since it uses less digits than its factorization.

81361104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936 (or 930 counting only the distinct ones).

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

The square root of 81361104 is about 9020.0390243058. The cubic root of 81361104 is about 433.3168835307.

The spelling of 81361104 in words is "eighty-one million, three hundred sixty-one thousand, one hundred four".