8641421 has 2 divisors, whose sum is σ = 8641422. Its totient is φ = 8641420.

The previous prime is 8641361. The next prime is 8641429. The reversal of 8641421 is 1241468.

8641421 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7344100 + 1297321 = 2710^2 + 1139^2 .

It is a cyclic number.

It is not a de Polignac number, because 8641421 - 2²² = 4447117 is a prime.

It is equal to p₅₈₀₀₄₉ and since 8641421 and 580049 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8641429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4320710 + 4320711.

It is an arithmetic number, because the mean of its divisors is an integer number (4320711).

Almost surely, 2^8641421 is an apocalyptic number.

It is an amenable number.

8641421 is a deficient number, since it is larger than the sum of its proper divisors (1).

8641421 is an equidigital number, since it uses as much as digits as its factorization.

8641421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 26.

The square root of 8641421 is about 2939.6293984106. The cubic root of 8641421 is about 205.2083624096.

Adding to 8641421 its reverse (1241468), we get a palindrome (9882889).

The spelling of 8641421 in words is "eight million, six hundred forty-one thousand, four hundred twenty-one".