81752730 has 64 divisors (see below), whose sum is σ = 201813120. Its totient is φ = 21187584.

The previous prime is 81752719. The next prime is 81752767. The reversal of 81752730 is 3725718.

It is a junction number, because it is equal to n+sod(n) for n = 81752691 and 81752700.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 178662 + ... + 179118.

It is an arithmetic number, because the mean of its divisors is an integer number (3153330).

Almost surely, 2^81752730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81752730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100906560).

81752730 is an abundant number, since it is smaller than the sum of its proper divisors (120060390).

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

81752730 is a wasteful number, since it uses less digits than its factorization.

81752730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623.

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 81752730 is about 9041.7216280972. The cubic root of 81752730 is about 434.0110178632.

The spelling of 81752730 in words is "eighty-one million, seven hundred fifty-two thousand, seven hundred thirty".