82787281 has 4 divisors (see below), whose sum is σ = 86386752. Its totient is φ = 79187812.

The previous prime is 82787279. The next prime is 82787293. The reversal of 82787281 is 18278728.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 82787281 - 2¹ = 82787279 is a prime.

It is a super-2 number, since 2×82787281² = 13707467790745922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82787681) 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 in 3 ways as a sum of consecutive naturals, for example, 1799701 + ... + 1799746.

It is an arithmetic number, because the mean of its divisors is an integer number (21596688).

Almost surely, 2^82787281 is an apocalyptic number.

It is an amenable number.

82787281 is a deficient number, since it is larger than the sum of its proper divisors (3599471).

82787281 is a wasteful number, since it uses less digits than its factorization.

82787281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3599470.

The product of its digits is 100352, while the sum is 43.

The square root of 82787281 is about 9098.7516176671. The cubic root of 82787281 is about 435.8340996208.

The spelling of 82787281 in words is "eighty-two million, seven hundred eighty-seven thousand, two hundred eighty-one".