81512960 has 80 divisors (see below), whose sum is σ = 207047016. Its totient is φ = 30670848.

The previous prime is 81512957. The next prime is 81512969. The reversal of 81512960 is 6921518.

It can be written as a sum of positive squares in 4 ways, for example, as 53465344 + 28047616 = 7312^2 + 5296^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (81512969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42584 + ... + 44456.

Almost surely, 2^81512960 is an apocalyptic number.

81512960 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 81512960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103523508).

81512960 is an abundant number, since it is smaller than the sum of its proper divisors (125534056).

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

81512960 is a wasteful number, since it uses less digits than its factorization.

81512960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1913 (or 1897 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 81512960 is about 9028.4528021140. The cubic root of 81512960 is about 433.5863033123.

It can be divided in two parts, 8151 and 2960, that added together give a palindrome (11111).

The spelling of 81512960 in words is "eighty-one million, five hundred twelve thousand, nine hundred sixty".