6617521 has 2 divisors, whose sum is σ = 6617522. Its totient is φ = 6617520.

The previous prime is 6617503. The next prime is 6617531. The reversal of 6617521 is 1257166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5688225 + 929296 = 2385^2 + 964^2 .

It is a cyclic number.

It is not a de Polignac number, because 6617521 - 2⁵ = 6617489 is a prime.

6617521 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6617521.

It is not a weakly prime, because it can be changed into another prime (6617531) 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, 3308760 + 3308761.

It is an arithmetic number, because the mean of its divisors is an integer number (3308761).

Almost surely, 2^6617521 is an apocalyptic number.

It is an amenable number.

6617521 is a deficient number, since it is larger than the sum of its proper divisors (1).

6617521 is an equidigital number, since it uses as much as digits as its factorization.

6617521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 28.

The square root of 6617521 is about 2572.4542755898. The cubic root of 6617521 is about 187.7435862284.

The spelling of 6617521 in words is "six million, six hundred seventeen thousand, five hundred twenty-one".