166872121481 has 4 divisors (see below), whose sum is σ = 179708438532. Its totient is φ = 154035804432.

The previous prime is 166872121447. The next prime is 166872121483. The reversal of 166872121481 is 184121278661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14522419081 + 152349702400 = 120509^2 + 390320^2 .

It is a cyclic number.

It is not a de Polignac number, because 166872121481 - 2⁶ = 166872121417 is a prime.

It is a super-2 number, since 2×166872121481² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166872121483) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6418158506 + ... + 6418158531.

It is an arithmetic number, because the mean of its divisors is an integer number (44927109633).

Almost surely, 2^166872121481 is an apocalyptic number.

It is an amenable number.

166872121481 is a deficient number, since it is larger than the sum of its proper divisors (12836317051).

166872121481 is a wasteful number, since it uses less digits than its factorization.

166872121481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12836317050.

The product of its digits is 258048, while the sum is 47.

The spelling of 166872121481 in words is "one hundred sixty-six billion, eight hundred seventy-two million, one hundred twenty-one thousand, four hundred eighty-one".