66610522971729 has 81 divisors (see below), whose sum is σ = 110565543801531. Its totient is φ = 38611204853760.

The previous prime is 66610522971719. The next prime is 66610522971749. The reversal of 66610522971729 is 92717922501666.

The square root of 66610522971729 is 8161527.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 63090216414225 + 3520306557504 = 7942935^2 + 1876248^2 .

It is not a de Polignac number, because 66610522971729 - 2³³ = 66601933037137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66610522971719) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 6194593617 + ... + 6194604369.

Almost surely, 2^{66610522971729} is an apocalyptic number.

66610522971729 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

66610522971729 is the 8161527-th square number.

66610522971729 is the 4080764-th centered octagonal number.

It is an amenable number.

66610522971729 is a deficient number, since it is larger than the sum of its proper divisors (43955020829802).

66610522971729 is an equidigital number, since it uses as much as digits as its factorization.

66610522971729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21580 (or 10790 counting only the distinct ones).

The product of its (nonzero) digits is 34292160, while the sum is 63.

The spelling of 66610522971729 in words is "sixty-six trillion, six hundred ten billion, five hundred twenty-two million, nine hundred seventy-one thousand, seven hundred twenty-nine".