6541621 has 2 divisors, whose sum is σ = 6541622. Its totient is φ = 6541620.

The previous prime is 6541609. The next prime is 6541663. The reversal of 6541621 is 1261456.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5948721 + 592900 = 2439^2 + 770^2 .

It is a cyclic number.

It is not a de Polignac number, because 6541621 - 2⁹ = 6541109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6541021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3270810 + 3270811.

It is an arithmetic number, because the mean of its divisors is an integer number (3270811).

Almost surely, 2^6541621 is an apocalyptic number.

It is an amenable number.

6541621 is a deficient number, since it is larger than the sum of its proper divisors (1).

6541621 is an equidigital number, since it uses as much as digits as its factorization.

6541621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 25.

The square root of 6541621 is about 2557.6592814525. The cubic root of 6541621 is about 187.0230461459.

The spelling of 6541621 in words is "six million, five hundred forty-one thousand, six hundred twenty-one".