66735521 has 2 divisors, whose sum is σ = 66735522. Its totient is φ = 66735520.

The previous prime is 66735511. The next prime is 66735541. The reversal of 66735521 is 12553766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58675600 + 8059921 = 7660^2 + 2839^2 .

It is a cyclic number.

It is not a de Polignac number, because 66735521 - 2¹⁰ = 66734497 is a prime.

It is not a weakly prime, because it can be changed into another prime (66735511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33367760 + 33367761.

It is an arithmetic number, because the mean of its divisors is an integer number (33367761).

Almost surely, 2^66735521 is an apocalyptic number.

It is an amenable number.

66735521 is a deficient number, since it is larger than the sum of its proper divisors (1).

66735521 is an equidigital number, since it uses as much as digits as its factorization.

66735521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 35.

The square root of 66735521 is about 8169.1811707172. The cubic root of 66735521 is about 405.6196803283.

The spelling of 66735521 in words is "sixty-six million, seven hundred thirty-five thousand, five hundred twenty-one".