166418281 has 2 divisors, whose sum is σ = 166418282. Its totient is φ = 166418280.

The previous prime is 166418279. The next prime is 166418333. The reversal of 166418281 is 182814661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166410000 + 8281 = 12900^2 + 91^2 .

It is a cyclic number.

It is not a de Polignac number, because 166418281 - 2¹ = 166418279 is a prime.

It is a super-2 number, since 2×166418281² = 55390088501989922, which contains 22 as substring.

Together with 166418279, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 166418281.

It is not a weakly prime, because it can be changed into another prime (166418201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83209140 + 83209141.

It is an arithmetic number, because the mean of its divisors is an integer number (83209141).

Almost surely, 2^166418281 is an apocalyptic number.

It is an amenable number.

166418281 is a deficient number, since it is larger than the sum of its proper divisors (1).

166418281 is an equidigital number, since it uses as much as digits as its factorization.

166418281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18432, while the sum is 37.

The square root of 166418281 is about 12900.3209649993. The cubic root of 166418281 is about 550.0476884270.

It can be divided in two parts, 16641 and 8281, that multiplied together give a square (137804121 = 11739²).

The spelling of 166418281 in words is "one hundred sixty-six million, four hundred eighteen thousand, two hundred eighty-one".