82991785 has 8 divisors (see below), whose sum is σ = 99659016. Its totient is φ = 66347520.

The previous prime is 82991771. The next prime is 82991789. The reversal of 82991785 is 58719928.

It can be written as a sum of positive squares in 4 ways, for example, as 25110121 + 57881664 = 5011^2 + 7608^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 82991785 - 2⁹ = 82991273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82991789) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3595 + ... + 13375.

It is an arithmetic number, because the mean of its divisors is an integer number (12457377).

Almost surely, 2^82991785 is an apocalyptic number.

It is an amenable number.

82991785 is a deficient number, since it is larger than the sum of its proper divisors (16667231).

82991785 is a wasteful number, since it uses less digits than its factorization.

82991785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11483.

The product of its digits is 362880, while the sum is 49.

The square root of 82991785 is about 9109.9827112899. The cubic root of 82991785 is about 436.1926753411.

The spelling of 82991785 in words is "eighty-two million, nine hundred ninety-one thousand, seven hundred eighty-five".