81751282 has 4 divisors (see below), whose sum is σ = 122626926. Its totient is φ = 40875640.

The previous prime is 81751279. The next prime is 81751289. The reversal of 81751282 is 28215718.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 28215718 = 2 ⋅14107859.

It can be written as a sum of positive squares in only one way, i.e., 80084601 + 1666681 = 8949^2 + 1291^2 .

It is not an unprimeable number, because it can be changed into a prime (81751289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20437819 + ... + 20437822.

Almost surely, 2^81751282 is an apocalyptic number.

81751282 is a deficient number, since it is larger than the sum of its proper divisors (40875644).

81751282 is a wasteful number, since it uses less digits than its factorization.

81751282 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40875643.

The product of its digits is 8960, while the sum is 34.

The square root of 81751282 is about 9041.6415544966. The cubic root of 81751282 is about 434.0084554548.

The spelling of 81751282 in words is "eighty-one million, seven hundred fifty-one thousand, two hundred eighty-two".