81458784 has 120 divisors (see below), whose sum is σ = 261438408. Its totient is φ = 24675840.

The previous prime is 81458771. The next prime is 81458789. The reversal of 81458784 is 48785418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81458789) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 27084 + ... + 29940.

Almost surely, 2^81458784 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 81458784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130719204).

81458784 is an abundant number, since it is smaller than the sum of its proper divisors (179979624).

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

81458784 is a wasteful number, since it uses less digits than its factorization.

81458784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2890 (or 2873 counting only the distinct ones).

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

The square root of 81458784 is about 9025.4520108413. The cubic root of 81458784 is about 433.4902237950.

The spelling of 81458784 in words is "eighty-one million, four hundred fifty-eight thousand, seven hundred eighty-four".