8122421 has 2 divisors, whose sum is σ = 8122422. Its totient is φ = 8122420.

The previous prime is 8122417. The next prime is 8122501. The reversal of 8122421 is 1242218.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8059921 + 62500 = 2839^2 + 250^2 .

It is a cyclic number.

It is not a de Polignac number, because 8122421 - 2² = 8122417 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 8122393 and 8122402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8122021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4061210 + 4061211.

It is an arithmetic number, because the mean of its divisors is an integer number (4061211).

Almost surely, 2^8122421 is an apocalyptic number.

It is an amenable number.

8122421 is a deficient number, since it is larger than the sum of its proper divisors (1).

8122421 is an equidigital number, since it uses as much as digits as its factorization.

8122421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 256, while the sum is 20.

The square root of 8122421 is about 2849.9861403172. The cubic root of 8122421 is about 201.0150150083.

Adding to 8122421 its reverse (1242218), we get a palindrome (9364639).

The spelling of 8122421 in words is "eight million, one hundred twenty-two thousand, four hundred twenty-one".