81114720 has 96 divisors (see below), whose sum is σ = 256773888. Its totient is φ = 21523968.

The previous prime is 81114713. The next prime is 81114757. The reversal of 81114720 is 2741118.

It is a tau number, because it is divible by the number of its divisors (96).

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, 166317 + ... + 166803.

It is an arithmetic number, because the mean of its divisors is an integer number (2674728).

Almost surely, 2^81114720 is an apocalyptic number.

81114720 is a gapful number since it is divisible by the number (80) 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 81114720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128386944).

81114720 is an abundant number, since it is smaller than the sum of its proper divisors (175659168).

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

81114720 is a wasteful number, since it uses less digits than its factorization.

81114720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 81114720 is about 9006.3710782979. The cubic root of 81114720 is about 432.8790400071.

Adding to 81114720 its reverse (2741118), we get a palindrome (83855838).

The spelling of 81114720 in words is "eighty-one million, one hundred fourteen thousand, seven hundred twenty".