66121057201 has 32 divisors (see below), whose sum is σ = 72042929280. Its totient is φ = 60451083264.

The previous prime is 66121057193. The next prime is 66121057229. The reversal of 66121057201 is 10275012166.

It is a cyclic number.

It is not a de Polignac number, because 66121057201 - 2³ = 66121057193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66121057231) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85537851 + ... + 85538623.

It is an arithmetic number, because the mean of its divisors is an integer number (2251341540).

Almost surely, 2^66121057201 is an apocalyptic number.

It is an amenable number.

66121057201 is a deficient number, since it is larger than the sum of its proper divisors (5921872079).

66121057201 is a wasteful number, since it uses less digits than its factorization.

66121057201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665.

The product of its (nonzero) digits is 5040, while the sum is 31.

Adding to 66121057201 its reverse (10275012166), we get a palindrome (76396069367).

The spelling of 66121057201 in words is "sixty-six billion, one hundred twenty-one million, fifty-seven thousand, two hundred one".