8500421 has 2 divisors, whose sum is σ = 8500422. Its totient is φ = 8500420.

The previous prime is 8500403. The next prime is 8500433. The reversal of 8500421 is 1240058.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8491396 + 9025 = 2914^2 + 95^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8500421 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 8500393 and 8500402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8500021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4250210 + 4250211.

It is an arithmetic number, because the mean of its divisors is an integer number (4250211).

Almost surely, 2^8500421 is an apocalyptic number.

It is an amenable number.

8500421 is a deficient number, since it is larger than the sum of its proper divisors (1).

8500421 is an equidigital number, since it uses as much as digits as its factorization.

8500421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 8500421 is about 2915.5481474330. The cubic root of 8500421 is about 204.0861244065.

Adding to 8500421 its reverse (1240058), we get a palindrome (9740479).

The spelling of 8500421 in words is "eight million, five hundred thousand, four hundred twenty-one".