81445360 has 40 divisors (see below), whose sum is σ = 193398336. Its totient is φ = 31883520.

The previous prime is 81445349. The next prime is 81445363. The reversal of 81445360 is 6354418.

It is a happy number.

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 (81445363) 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 7 ways as a sum of consecutive naturals, for example, 7071 + ... + 14590.

Almost surely, 2^81445360 is an apocalyptic number.

81445360 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81445360 is an abundant number, since it is smaller than the sum of its proper divisors (111952976).

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

81445360 is a wasteful number, since it uses less digits than its factorization.

81445360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21721 (or 21715 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 81445360 is about 9024.7083055354. The cubic root of 81445360 is about 433.4664101469.

Adding to 81445360 its reverse (6354418), we get a palindrome (87799778).

The spelling of 81445360 in words is "eighty-one million, four hundred forty-five thousand, three hundred sixty".