66533557 has 2 divisors, whose sum is σ = 66533558. Its totient is φ = 66533556.

The previous prime is 66533543. The next prime is 66533581. The reversal of 66533557 is 75533566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40462321 + 26071236 = 6361^2 + 5106^2 .

It is a cyclic number.

It is not a de Polignac number, because 66533557 - 2¹⁵ = 66500789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66533507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33266778 + 33266779.

It is an arithmetic number, because the mean of its divisors is an integer number (33266779).

Almost surely, 2^66533557 is an apocalyptic number.

It is an amenable number.

66533557 is a deficient number, since it is larger than the sum of its proper divisors (1).

66533557 is an equidigital number, since it uses as much as digits as its factorization.

66533557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 283500, while the sum is 40.

The square root of 66533557 is about 8156.8104673334. The cubic root of 66533557 is about 405.2100866027.

Subtracting 66533557 from its reverse (75533566), we obtain a palindrome (9000009).

The spelling of 66533557 in words is "sixty-six million, five hundred thirty-three thousand, five hundred fifty-seven".