81522160 has 40 divisors (see below), whose sum is σ = 199518480. Its totient is φ = 30892032.

The previous prime is 81522151. The next prime is 81522163. The reversal of 81522160 is 6122518.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81522163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25297 + ... + 28336.

It is an arithmetic number, because the mean of its divisors is an integer number (4987962).

Almost surely, 2^81522160 is an apocalyptic number.

81522160 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81522160 is an abundant number, since it is smaller than the sum of its proper divisors (117996320).

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

81522160 is a wasteful number, since it uses less digits than its factorization.

81522160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53665 (or 53659 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 81522160 is about 9028.9622881038. The cubic root of 81522160 is about 433.6026150085.

Adding to 81522160 its reverse (6122518), we get a palindrome (87644678).

The spelling of 81522160 in words is "eighty-one million, five hundred twenty-two thousand, one hundred sixty".