81934368 has 48 divisors (see below), whose sum is σ = 216074880. Its totient is φ = 27184896.

The previous prime is 81934361. The next prime is 81934399. The reversal of 81934368 is 86343918.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (81934361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20121 + ... + 23847.

It is an arithmetic number, because the mean of its divisors is an integer number (4501560).

Almost surely, 2^81934368 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 81934368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108037440).

81934368 is an abundant number, since it is smaller than the sum of its proper divisors (134140512).

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

81934368 is a wasteful number, since it uses less digits than its factorization.

81934368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3969 (or 3961 counting only the distinct ones).

The product of its digits is 124416, while the sum is 42.

The square root of 81934368 is about 9051.7604917497. The cubic root of 81934368 is about 434.3322082857.

It can be divided in two parts, 8193 and 4368, that added together give a triangular number (12561 = T₁₅₈).

The spelling of 81934368 in words is "eighty-one million, nine hundred thirty-four thousand, three hundred sixty-eight".