66628733 has 2 divisors, whose sum is σ = 66628734. Its totient is φ = 66628732.

The previous prime is 66628691. The next prime is 66628739. The reversal of 66628733 is 33782666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65885689 + 743044 = 8117^2 + 862^2 .

It is a cyclic number.

It is not a de Polignac number, because 66628733 - 2¹⁴ = 66612349 is a prime.

It is a super-2 number, since 2×66628733² = 8878776122370578, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66628739) 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, 33314366 + 33314367.

It is an arithmetic number, because the mean of its divisors is an integer number (33314367).

Almost surely, 2^66628733 is an apocalyptic number.

It is an amenable number.

66628733 is a deficient number, since it is larger than the sum of its proper divisors (1).

66628733 is an equidigital number, since it uses as much as digits as its factorization.

66628733 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 41.

The square root of 66628733 is about 8162.6425255551. The cubic root of 66628733 is about 405.4032117058.

The spelling of 66628733 in words is "sixty-six million, six hundred twenty-eight thousand, seven hundred thirty-three".