82135681 has 4 divisors (see below), whose sum is σ = 82211652. Its totient is φ = 82059712.

The previous prime is 82135679. The next prime is 82135693. The reversal of 82135681 is 18653128.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11424400 + 70711281 = 3380^2 + 8409^2 .

It is a cyclic number.

It is not a de Polignac number, because 82135681 - 2¹ = 82135679 is a prime.

It is a super-2 number, since 2×82135681² = 13492540186667522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82135621) 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 3 ways as a sum of consecutive naturals, for example, 36340 + ... + 38533.

It is an arithmetic number, because the mean of its divisors is an integer number (20552913).

Almost surely, 2^82135681 is an apocalyptic number.

It is an amenable number.

82135681 is a deficient number, since it is larger than the sum of its proper divisors (75971).

82135681 is a wasteful number, since it uses less digits than its factorization.

82135681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75970.

The product of its digits is 11520, while the sum is 34.

The square root of 82135681 is about 9062.8737716025. The cubic root of 82135681 is about 434.6876358830.

The spelling of 82135681 in words is "eighty-two million, one hundred thirty-five thousand, six hundred eighty-one".