166431324321 has 16 divisors (see below), whose sum is σ = 246577968000. Its totient is φ = 110948346864.

The previous prime is 166431324281. The next prime is 166431324341. The reversal of 166431324321 is 123423134661.

166431324321 is a `hidden beast` number, since 1 + 6 + 6 + 4 + 3 + 1 + 324 + 321 = 666.

It is not a de Polignac number, because 166431324321 - 2³⁰ = 165357582497 is a prime.

It is a super-2 number, since 2×166431324321² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166431324341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 391060 + ... + 696986.

It is an arithmetic number, because the mean of its divisors is an integer number (15411123000).

Almost surely, 2^166431324321 is an apocalyptic number.

It is an amenable number.

166431324321 is a deficient number, since it is larger than the sum of its proper divisors (80146643679).

166431324321 is a wasteful number, since it uses less digits than its factorization.

166431324321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326085 (or 326079 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

Adding to 166431324321 its reverse (123423134661), we get a palindrome (289854458982).

It can be divided in two parts, 16643 and 1324321, that added together give a square (1340964 = 1158²).

The spelling of 166431324321 in words is "one hundred sixty-six billion, four hundred thirty-one million, three hundred twenty-four thousand, three hundred twenty-one".