66530441521 has 2 divisors, whose sum is σ = 66530441522. Its totient is φ = 66530441520.

The previous prime is 66530441407. The next prime is 66530441563. The reversal of 66530441521 is 12514403566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57581281521 + 8949160000 = 239961^2 + 94600^2 .

It is a cyclic number.

It is not a de Polignac number, because 66530441521 - 2¹⁵ = 66530408753 is a prime.

It is not a weakly prime, because it can be changed into another prime (66530441581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33265220760 + 33265220761.

It is an arithmetic number, because the mean of its divisors is an integer number (33265220761).

Almost surely, 2^66530441521 is an apocalyptic number.

It is an amenable number.

66530441521 is a deficient number, since it is larger than the sum of its proper divisors (1).

66530441521 is an equidigital number, since it uses as much as digits as its factorization.

66530441521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 66530441521 in words is "sixty-six billion, five hundred thirty million, four hundred forty-one thousand, five hundred twenty-one".