81537960 has 160 divisors (see below), whose sum is σ = 286374240. Its totient is φ = 18571392.

The previous prime is 81537947. The next prime is 81537961. The reversal of 81537960 is 6973518.

It is not an unprimeable number, because it can be changed into a prime (81537961) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 287979 + ... + 288261.

It is an arithmetic number, because the mean of its divisors is an integer number (1789839).

Almost surely, 2^81537960 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 81537960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143187120).

81537960 is an abundant number, since it is smaller than the sum of its proper divisors (204836280).

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

81537960 is a wasteful number, since it uses less digits than its factorization.

81537960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 39.

The square root of 81537960 is about 9029.8372078349. The cubic root of 81537960 is about 433.6306257104.

The spelling of 81537960 in words is "eighty-one million, five hundred thirty-seven thousand, nine hundred sixty".