81478912 has 36 divisors (see below), whose sum is σ = 167902336. Its totient is φ = 39421440.

The previous prime is 81478907. The next prime is 81478913. The reversal of 81478912 is 21987418.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81478913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2803 + ... + 13069.

Almost surely, 2^81478912 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 81478912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83951168).

81478912 is an abundant number, since it is smaller than the sum of its proper divisors (86423424).

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

81478912 is a wasteful number, since it uses less digits than its factorization.

81478912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10314 (or 10300 counting only the distinct ones).

The product of its digits is 32256, while the sum is 40.

The square root of 81478912 is about 9026.5670107744. The cubic root of 81478912 is about 433.5259251737.

The spelling of 81478912 in words is "eighty-one million, four hundred seventy-eight thousand, nine hundred twelve".