81548520 has 64 divisors (see below), whose sum is σ = 246456000. Its totient is φ = 21585408.

The previous prime is 81548497. The next prime is 81548539. The reversal of 81548520 is 2584518.

It is a super-2 number, since 2×81548520² = 13300322228380800, which contains 22 as substring.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 14236 + ... + 19124.

It is an arithmetic number, because the mean of its divisors is an integer number (3850875).

Almost surely, 2^81548520 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 81548520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123228000).

81548520 is an abundant number, since it is smaller than the sum of its proper divisors (164907480).

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

81548520 is a wasteful number, since it uses less digits than its factorization.

81548520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5042 (or 5038 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 33.

The square root of 81548520 is about 9030.4219170535. The cubic root of 81548520 is about 433.6493447698.

The spelling of 81548520 in words is "eighty-one million, five hundred forty-eight thousand, five hundred twenty".