66517849 has 2 divisors, whose sum is σ = 66517850. Its totient is φ = 66517848.

The previous prime is 66517837. The next prime is 66517883. The reversal of 66517849 is 94871566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59783824 + 6734025 = 7732^2 + 2595^2 .

It is a cyclic number.

It is not a de Polignac number, because 66517849 - 2¹⁹ = 65993561 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66517799 and 66517808.

It is not a weakly prime, because it can be changed into another prime (66517349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33258924 + 33258925.

It is an arithmetic number, because the mean of its divisors is an integer number (33258925).

Almost surely, 2^66517849 is an apocalyptic number.

It is an amenable number.

66517849 is a deficient number, since it is larger than the sum of its proper divisors (1).

66517849 is an equidigital number, since it uses as much as digits as its factorization.

66517849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The square root of 66517849 is about 8155.8475341316. The cubic root of 66517849 is about 405.1781952219.

It can be divided in two parts, 6 and 6517849, that added together give a triangular number (6517855 = T₃₆₁₀).

The spelling of 66517849 in words is "sixty-six million, five hundred seventeen thousand, eight hundred forty-nine".