6653521561 has 2 divisors, whose sum is σ = 6653521562. Its totient is φ = 6653521560.

The previous prime is 6653521507. The next prime is 6653521619. The reversal of 6653521561 is 1651253566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5000611225 + 1652910336 = 70715^2 + 40656^2 .

It is a cyclic number.

It is not a de Polignac number, because 6653521561 - 2¹¹ = 6653519513 is a prime.

It is not a weakly prime, because it can be changed into another prime (6653521961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3326760780 + 3326760781.

It is an arithmetic number, because the mean of its divisors is an integer number (3326760781).

Almost surely, 2^6653521561 is an apocalyptic number.

It is an amenable number.

6653521561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6653521561 is an equidigital number, since it uses as much as digits as its factorization.

6653521561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162000, while the sum is 40.

The square root of 6653521561 is about 81569.1213695477. The cubic root of 6653521561 is about 1880.8342420407.

The spelling of 6653521561 in words is "six billion, six hundred fifty-three million, five hundred twenty-one thousand, five hundred sixty-one".