8212021 has 2 divisors, whose sum is σ = 8212022. Its totient is φ = 8212020.

The previous prime is 8212019. The next prime is 8212063. The reversal of 8212021 is 1202128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8059921 + 152100 = 2839^2 + 390^2 .

It is a cyclic number.

It is not a de Polignac number, because 8212021 - 2¹ = 8212019 is a prime.

Together with 8212019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 8211986 and 8212004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8212091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4106010 + 4106011.

It is an arithmetic number, because the mean of its divisors is an integer number (4106011).

Almost surely, 2^8212021 is an apocalyptic number.

It is an amenable number.

8212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

8212021 is an equidigital number, since it uses as much as digits as its factorization.

8212021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 8212021 is about 2865.6624016098. The cubic root of 8212021 is about 201.7514588529.

Adding to 8212021 its reverse (1202128), we get a palindrome (9414149).

The spelling of 8212021 in words is "eight million, two hundred twelve thousand, twenty-one".