6520450661 has 2 divisors, whose sum is σ = 6520450662. Its totient is φ = 6520450660.

The previous prime is 6520450603. The next prime is 6520450669. The reversal of 6520450661 is 1660540256.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6364050625 + 156400036 = 79775^2 + 12506^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6520450661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6520450669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3260225330 + 3260225331.

It is an arithmetic number, because the mean of its divisors is an integer number (3260225331).

Almost surely, 2^6520450661 is an apocalyptic number.

It is an amenable number.

6520450661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6520450661 is an equidigital number, since it uses as much as digits as its factorization.

6520450661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 6520450661 is about 80749.3074954826. The cubic root of 6520450661 is about 1868.2107683143.

The spelling of 6520450661 in words is "six billion, five hundred twenty million, four hundred fifty thousand, six hundred sixty-one".