81487472 has 40 divisors (see below), whose sum is σ = 175917312. Its totient is φ = 36248000.

The previous prime is 81487457. The next prime is 81487489. The reversal of 81487472 is 27478418.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3347 + ... + 13197.

Almost surely, 2^81487472 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 81487472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87958656).

81487472 is an abundant number, since it is smaller than the sum of its proper divisors (94429840).

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

81487472 is a wasteful number, since it uses less digits than its factorization.

81487472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9917 (or 9911 counting only the distinct ones).

The product of its digits is 100352, while the sum is 41.

The square root of 81487472 is about 9027.0411542210. The cubic root of 81487472 is about 433.5411064105.

The spelling of 81487472 in words is "eighty-one million, four hundred eighty-seven thousand, four hundred seventy-two".