81381248 has 32 divisors (see below), whose sum is σ = 174601560. Its totient is φ = 37559808.

The previous prime is 81381217. The next prime is 81381257. The reversal of 81381248 is 84218318.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22790 + ... + 26117.

Almost surely, 2^81381248 is an apocalyptic number.

It is an amenable number.

81381248 is an abundant number, since it is smaller than the sum of its proper divisors (93220312).

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

81381248 is a wasteful number, since it uses less digits than its factorization.

81381248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48934 (or 48922 counting only the distinct ones).

The product of its digits is 12288, while the sum is 35.

The square root of 81381248 is about 9021.1555800795. The cubic root of 81381248 is about 433.3526418747.

The spelling of 81381248 in words is "eighty-one million, three hundred eighty-one thousand, two hundred forty-eight".