82123785 has 12 divisors (see below), whose sum is σ = 142347972. Its totient is φ = 43799328.

The previous prime is 82123781. The next prime is 82123813. The reversal of 82123785 is 58732128.

It can be written as a sum of positive squares in 2 ways, for example, as 17867529 + 64256256 = 4227^2 + 8016^2 .

It is not a de Polignac number, because 82123785 - 2² = 82123781 is a prime.

It is not an unprimeable number, because it can be changed into a prime (82123781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 912442 + ... + 912531.

It is an arithmetic number, because the mean of its divisors is an integer number (11862331).

Almost surely, 2^82123785 is an apocalyptic number.

It is an amenable number.

82123785 is a deficient number, since it is larger than the sum of its proper divisors (60224187).

82123785 is a wasteful number, since it uses less digits than its factorization.

82123785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1824984 (or 1824981 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 82123785 is about 9062.2174438710. The cubic root of 82123785 is about 434.6666490893. Note that the first 4 decimals are identical.

The spelling of 82123785 in words is "eighty-two million, one hundred twenty-three thousand, seven hundred eighty-five".