166560212121 has 8 divisors (see below), whose sum is σ = 222251514144. Its totient is φ = 110954525760.

The previous prime is 166560212101. The next prime is 166560212153. The reversal of 166560212121 is 121212065661.

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

It is not a de Polignac number, because 166560212121 - 2¹¹ = 166560210073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166560212101) 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, 21399375 + ... + 21407156.

It is an arithmetic number, because the mean of its divisors is an integer number (27781439268).

Almost surely, 2^166560212121 is an apocalyptic number.

It is an amenable number.

166560212121 is a deficient number, since it is larger than the sum of its proper divisors (55691302023).

166560212121 is a wasteful number, since it uses less digits than its factorization.

166560212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42807831.

The product of its (nonzero) digits is 8640, while the sum is 33.

Adding to 166560212121 its reverse (121212065661), we get a palindrome (287772277782).

The spelling of 166560212121 in words is "one hundred sixty-six billion, five hundred sixty million, two hundred twelve thousand, one hundred twenty-one".