81350320 has 20 divisors (see below), whose sum is σ = 189139680. Its totient is φ = 32540096.

The previous prime is 81350303. The next prime is 81350323. The reversal of 81350320 is 2305318.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 81350291 and 81350300.

It is not an unprimeable number, because it can be changed into a prime (81350323) 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 3 ways as a sum of consecutive naturals, for example, 508360 + ... + 508519.

It is an arithmetic number, because the mean of its divisors is an integer number (9456984).

Almost surely, 2^81350320 is an apocalyptic number.

81350320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81350320 is an abundant number, since it is smaller than the sum of its proper divisors (107789360).

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

81350320 is a wasteful number, since it uses less digits than its factorization.

81350320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016892 (or 1016886 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 81350320 is about 9019.4412243775. The cubic root of 81350320 is about 433.2977380361.

Adding to 81350320 its reverse (2305318), we get a palindrome (83655638).

The spelling of 81350320 in words is "eighty-one million, three hundred fifty thousand, three hundred twenty".