166431324281 has 2 divisors, whose sum is σ = 166431324282. Its totient is φ = 166431324280.

The previous prime is 166431324271. The next prime is 166431324341. The reversal of 166431324281 is 182423134661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96280504681 + 70150819600 = 310291^2 + 264860^2 .

It is a cyclic number.

It is not a de Polignac number, because 166431324281 - 2³⁰ = 165357582457 is a prime.

It is a super-2 number, since 2×166431324281² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166431324221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83215662140 + 83215662141.

It is an arithmetic number, because the mean of its divisors is an integer number (83215662141).

Almost surely, 2^166431324281 is an apocalyptic number.

It is an amenable number.

166431324281 is a deficient number, since it is larger than the sum of its proper divisors (1).

166431324281 is an equidigital number, since it uses as much as digits as its factorization.

166431324281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 41.

The spelling of 166431324281 in words is "one hundred sixty-six billion, four hundred thirty-one million, three hundred twenty-four thousand, two hundred eighty-one".