82781439 has 48 divisors (see below), whose sum is σ = 129300480. Its totient is φ = 46949760.

The previous prime is 82781431. The next prime is 82781443. The reversal of 82781439 is 93418728.

It is not a de Polignac number, because 82781439 - 2³ = 82781431 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 82781439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82781431) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 361377 + ... + 361605.

It is an arithmetic number, because the mean of its divisors is an integer number (2693760).

Almost surely, 2^82781439 is an apocalyptic number.

82781439 is a deficient number, since it is larger than the sum of its proper divisors (46519041).

82781439 is a wasteful number, since it uses less digits than its factorization.

82781439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312 (or 299 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 82781439 is about 9098.4305789515. The cubic root of 82781439 is about 435.8238476326.

The spelling of 82781439 in words is "eighty-two million, seven hundred eighty-one thousand, four hundred thirty-nine".