66510566161 has 8 divisors (see below), whose sum is σ = 71805389544. Its totient is φ = 61241260800.

The previous prime is 66510566149. The next prime is 66510566191. The reversal of 66510566161 is 16166501566.

It can be written as a sum of positive squares in 4 ways, for example, as 35857209600 + 30653356561 = 189360^2 + 175081^2 .

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 66510566161 - 2¹³ = 66510557969 is a prime.

It is a super-2 number, since 2×66510566161² (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 (66510566191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6374086 + ... + 6384511.

It is an arithmetic number, because the mean of its divisors is an integer number (8975673693).

Almost surely, 2^66510566161 is an apocalyptic number.

It is an amenable number.

66510566161 is a deficient number, since it is larger than the sum of its proper divisors (5294823383).

66510566161 is a wasteful number, since it uses less digits than its factorization.

66510566161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12759011.

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 66510566161 in words is "sixty-six billion, five hundred ten million, five hundred sixty-six thousand, one hundred sixty-one".