81397548 has 60 divisors (see below), whose sum is σ = 220152240. Its totient is φ = 26193888.

The previous prime is 81397541. The next prime is 81397549. The reversal of 81397548 is 84579318.

81397548 is a `hidden beast` number, since 8 + 13 + 97 + 548 = 666.

It is not an unprimeable number, because it can be changed into a prime (81397541) 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, 5065 + ... + 13727.

It is an arithmetic number, because the mean of its divisors is an integer number (3669204).

Almost surely, 2^81397548 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 81397548, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110076120).

81397548 is an abundant number, since it is smaller than the sum of its proper divisors (138754692).

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

81397548 is a wasteful number, since it uses less digits than its factorization.

81397548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8708 (or 8697 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 81397548 is about 9022.0589667769. The cubic root of 81397548 is about 433.3815722761.

The spelling of 81397548 in words is "eighty-one million, three hundred ninety-seven thousand, five hundred forty-eight".