66613435577 has 8 divisors (see below), whose sum is σ = 72035215560. Its totient is φ = 61234179840.

The previous prime is 66613435571. The next prime is 66613435583. The reversal of 66613435577 is 77553431666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66613435571) and next prime (66613435583).

It can be written as a sum of positive squares in 4 ways, for example, as 12341210281 + 54272225296 = 111091^2 + 232964^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66613435577 - 2¹⁰ = 66613434553 is a prime.

It is a super-2 number, since 2×66613435577² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66613435571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10627802 + ... + 10634067.

It is an arithmetic number, because the mean of its divisors is an integer number (9004401945).

Almost surely, 2^66613435577 is an apocalyptic number.

It is an amenable number.

66613435577 is a deficient number, since it is larger than the sum of its proper divisors (5421779983).

66613435577 is a wasteful number, since it uses less digits than its factorization.

66613435577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21262123.

The product of its digits is 9525600, while the sum is 53.

The spelling of 66613435577 in words is "sixty-six billion, six hundred thirteen million, four hundred thirty-five thousand, five hundred seventy-seven".