81347872 has 24 divisors (see below), whose sum is σ = 167118336. Its totient is φ = 38905152.

The previous prime is 81347857. The next prime is 81347879. The reversal of 81347872 is 27874318.

It is not an unprimeable number, because it can be changed into a prime (81347879) 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, 54528 + ... + 55999.

It is an arithmetic number, because the mean of its divisors is an integer number (6963264).

Almost surely, 2^81347872 is an apocalyptic number.

It is an amenable number.

81347872 is an abundant number, since it is smaller than the sum of its proper divisors (85770464).

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

81347872 is a wasteful number, since it uses less digits than its factorization.

81347872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110560 (or 110552 counting only the distinct ones).

The product of its digits is 75264, while the sum is 40.

The square root of 81347872 is about 9019.3055165018. The cubic root of 81347872 is about 433.2933917163.

The spelling of 81347872 in words is "eighty-one million, three hundred forty-seven thousand, eight hundred seventy-two".