82028021 has 2 divisors, whose sum is σ = 82028022. Its totient is φ = 82028020.

The previous prime is 82028017. The next prime is 82028057. The reversal of 82028021 is 12082028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79744900 + 2283121 = 8930^2 + 1511^2 .

It is a cyclic number.

It is not a de Polignac number, because 82028021 - 2² = 82028017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82028071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41014010 + 41014011.

It is an arithmetic number, because the mean of its divisors is an integer number (41014011).

Almost surely, 2^82028021 is an apocalyptic number.

It is an amenable number.

82028021 is a deficient number, since it is larger than the sum of its proper divisors (1).

82028021 is an equidigital number, since it uses as much as digits as its factorization.

82028021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 82028021 is about 9056.9322068789. The cubic root of 82028021 is about 434.4976294109.

The spelling of 82028021 in words is "eighty-two million, twenty-eight thousand, twenty-one".