66777777533 has 2 divisors, whose sum is σ = 66777777534. Its totient is φ = 66777777532.

The previous prime is 66777777529. The next prime is 66777777557. The reversal of 66777777533 is 33577777766.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49407064729 + 17370712804 = 222277^2 + 131798^2 .

It is a cyclic number.

It is not a de Polignac number, because 66777777533 - 2² = 66777777529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66777777533.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66777777593) 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, 33388888766 + 33388888767.

It is an arithmetic number, because the mean of its divisors is an integer number (33388888767).

Almost surely, 2^66777777533 is an apocalyptic number.

It is an amenable number.

66777777533 is a deficient number, since it is larger than the sum of its proper divisors (1).

66777777533 is an equidigital number, since it uses as much as digits as its factorization.

66777777533 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 190591380, while the sum is 65.

The spelling of 66777777533 in words is "sixty-six billion, seven hundred seventy-seven million, seven hundred seventy-seven thousand, five hundred thirty-three".