82165021 has 2 divisors, whose sum is σ = 82165022. Its totient is φ = 82165020.

The previous prime is 82165003. The next prime is 82165043. The reversal of 82165021 is 12056128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69305625 + 12859396 = 8325^2 + 3586^2 .

It is a cyclic number.

It is not a de Polignac number, because 82165021 - 2¹³ = 82156829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82165051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41082510 + 41082511.

It is an arithmetic number, because the mean of its divisors is an integer number (41082511).

Almost surely, 2^82165021 is an apocalyptic number.

It is an amenable number.

82165021 is a deficient number, since it is larger than the sum of its proper divisors (1).

82165021 is an equidigital number, since it uses as much as digits as its factorization.

82165021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 82165021 is about 9064.4923189333. The cubic root of 82165021 is about 434.7393885309.

The spelling of 82165021 in words is "eighty-two million, one hundred sixty-five thousand, twenty-one".