83686021 has 2 divisors, whose sum is σ = 83686022. Its totient is φ = 83686020.

The previous prime is 83685997. The next prime is 83686027. The reversal of 83686021 is 12068638.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82901025 + 784996 = 9105^2 + 886^2 .

It is a cyclic number.

It is not a de Polignac number, because 83686021 - 2¹³ = 83677829 is a prime.

It is a super-3 number, since 3×83686021³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (83686027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41843010 + 41843011.

It is an arithmetic number, because the mean of its divisors is an integer number (41843011).

Almost surely, 2^83686021 is an apocalyptic number.

It is an amenable number.

83686021 is a deficient number, since it is larger than the sum of its proper divisors (1).

83686021 is an equidigital number, since it uses as much as digits as its factorization.

83686021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 83686021 is about 9148.0063948382. The cubic root of 83686021 is about 437.4055672103.

The spelling of 83686021 in words is "eighty-three million, six hundred eighty-six thousand, twenty-one".