82128757 has 4 divisors (see below), whose sum is σ = 82160416. Its totient is φ = 82097100.

The previous prime is 82128743. The next prime is 82128793. The reversal of 82128757 is 75782128.

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 a de Polignac number, because none of the positive numbers 2^k-82128757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82128707) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11553 + ... + 17254.

It is an arithmetic number, because the mean of its divisors is an integer number (20540104).

Almost surely, 2^82128757 is an apocalyptic number.

It is an amenable number.

82128757 is a deficient number, since it is larger than the sum of its proper divisors (31659).

82128757 is a wasteful number, since it uses less digits than its factorization.

82128757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31658.

The product of its digits is 62720, while the sum is 40.

The square root of 82128757 is about 9062.4917655135. The cubic root of 82128757 is about 434.6754208841.

The spelling of 82128757 in words is "eighty-two million, one hundred twenty-eight thousand, seven hundred fifty-seven".