81271242 has 32 divisors (see below), whose sum is σ = 194496960. Its totient is φ = 25006320.

The previous prime is 81271241. The next prime is 81271297. The reversal of 81271242 is 24217218.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81271241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57184 + ... + 58587.

It is an arithmetic number, because the mean of its divisors is an integer number (6078030).

Almost surely, 2^81271242 is an apocalyptic number.

81271242 is an abundant number, since it is smaller than the sum of its proper divisors (113225718).

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

81271242 is a wasteful number, since it uses less digits than its factorization.

81271242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115795 (or 115789 counting only the distinct ones).

The product of its digits is 1792, while the sum is 27.

The square root of 81271242 is about 9015.0564058136. The cubic root of 81271242 is about 433.1572943069.

The spelling of 81271242 in words is "eighty-one million, two hundred seventy-one thousand, two hundred forty-two".