81347056 has 120 divisors (see below), whose sum is σ = 199034880. Its totient is φ = 32006016.

The previous prime is 81347051. The next prime is 81347081. The reversal of 81347056 is 65074318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81347051) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 640465 + ... + 640591.

It is an arithmetic number, because the mean of its divisors is an integer number (1658624).

Almost surely, 2^81347056 is an apocalyptic number.

81347056 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81347056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99517440).

81347056 is an abundant number, since it is smaller than the sum of its proper divisors (117687824).

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

81347056 is a wasteful number, since it uses less digits than its factorization.

81347056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 81347056 is about 9019.2602800895. The cubic root of 81347056 is about 433.2919429237.

The spelling of 81347056 in words is "eighty-one million, three hundred forty-seven thousand, fifty-six".