6501421 has 2 divisors, whose sum is σ = 6501422. Its totient is φ = 6501420.

The previous prime is 6501419. The next prime is 6501431. The reversal of 6501421 is 1241056.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4888521 + 1612900 = 2211^2 + 1270^2 .

It is a cyclic number.

It is not a de Polignac number, because 6501421 - 2¹ = 6501419 is a prime.

Together with 6501419, it forms a pair of twin primes.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6501431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3250710 + 3250711.

It is an arithmetic number, because the mean of its divisors is an integer number (3250711).

Almost surely, 2^6501421 is an apocalyptic number.

It is an amenable number.

6501421 is a deficient number, since it is larger than the sum of its proper divisors (1).

6501421 is an equidigital number, since it uses as much as digits as its factorization.

6501421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 6501421 is about 2549.7884225951. The cubic root of 6501421 is about 186.6391565893.

Adding to 6501421 its reverse (1241056), we get a palindrome (7742477).

The spelling of 6501421 in words is "six million, five hundred one thousand, four hundred twenty-one".