81215328 has 48 divisors (see below), whose sum is σ = 213748416. Its totient is φ = 27000960.

The previous prime is 81215327. The next prime is 81215359. The reversal of 81215328 is 82351218.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 81215295 and 81215304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81215327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46275 + ... + 47997.

It is an arithmetic number, because the mean of its divisors is an integer number (4453092).

Almost surely, 2^81215328 is an apocalyptic number.

It is an amenable number.

81215328 is an abundant number, since it is smaller than the sum of its proper divisors (132533088).

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

81215328 is a wasteful number, since it uses less digits than its factorization.

81215328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2227 (or 2219 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 81215328 is about 9011.9547269169. The cubic root of 81215328 is about 433.0579352028.

The spelling of 81215328 in words is "eighty-one million, two hundred fifteen thousand, three hundred twenty-eight".