81648280 has 96 divisors (see below), whose sum is σ = 223250400. Its totient is φ = 26320896.

The previous prime is 81648257. The next prime is 81648313. The reversal of 81648280 is 8284618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 80416 + ... + 81424.

It is an arithmetic number, because the mean of its divisors is an integer number (2325525).

Almost surely, 2^81648280 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81648280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111625200).

81648280 is an abundant number, since it is smaller than the sum of its proper divisors (141602120).

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

81648280 is a wasteful number, since it uses less digits than its factorization.

81648280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061 (or 1040 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 81648280 is about 9035.9437802589. The cubic root of 81648280 is about 433.8261034650.

The spelling of 81648280 in words is "eighty-one million, six hundred forty-eight thousand, two hundred eighty".