81578484 has 72 divisors (see below), whose sum is σ = 229279232. Its totient is φ = 24287040.

The previous prime is 81578477. The next prime is 81578489. The reversal of 81578484 is 48487518.

It is a super-3 number, since 3×81578484³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81578489) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11697 + ... + 17319.

Almost surely, 2^81578484 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 81578484, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114639616).

81578484 is an abundant number, since it is smaller than the sum of its proper divisors (147700748).

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

81578484 is a wasteful number, since it uses less digits than its factorization.

81578484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5677 (or 5672 counting only the distinct ones).

The product of its digits is 286720, while the sum is 45.

The square root of 81578484 is about 9032.0808233762. The cubic root of 81578484 is about 433.7024513041.

It can be divided in two parts, 8157 and 8484, that added together give a square (16641 = 129²).

The spelling of 81578484 in words is "eighty-one million, five hundred seventy-eight thousand, four hundred eighty-four".