82311821 has 4 divisors (see below), whose sum is σ = 82350012. Its totient is φ = 82273632.

The previous prime is 82311797. The next prime is 82311833. The reversal of 82311821 is 12811328.

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 39866596 + 42445225 = 6314^2 + 6515^2 .

It is a cyclic number.

It is not a de Polignac number, because 82311821 - 2¹⁸ = 82049677 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 (82311881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15656 + ... + 20241.

It is an arithmetic number, because the mean of its divisors is an integer number (20587503).

Almost surely, 2^82311821 is an apocalyptic number.

It is an amenable number.

82311821 is a deficient number, since it is larger than the sum of its proper divisors (38191).

82311821 is a wasteful number, since it uses less digits than its factorization.

82311821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38190.

The product of its digits is 768, while the sum is 26.

The square root of 82311821 is about 9072.5862354678. The cubic root of 82311821 is about 434.9981432959.

The spelling of 82311821 in words is "eighty-two million, three hundred eleven thousand, eight hundred twenty-one".