81282872 has 32 divisors (see below), whose sum is σ = 168551280. Its totient is φ = 36437760.

The previous prime is 81282841. The next prime is 81282907. The reversal of 81282872 is 27828218.

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, 98 + ... + 12750.

Almost surely, 2^81282872 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 81282872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84275640).

81282872 is an abundant number, since it is smaller than the sum of its proper divisors (87268408).

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

81282872 is a wasteful number, since it uses less digits than its factorization.

81282872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12743 (or 12739 counting only the distinct ones).

The product of its digits is 28672, while the sum is 38.

The square root of 81282872 is about 9015.7014147542. The cubic root of 81282872 is about 433.1779550758.

The spelling of 81282872 in words is "eighty-one million, two hundred eighty-two thousand, eight hundred seventy-two".