66481517 has 2 divisors, whose sum is σ = 66481518. Its totient is φ = 66481516.

The previous prime is 66481507. The next prime is 66481553. The reversal of 66481517 is 71518466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57547396 + 8934121 = 7586^2 + 2989^2 .

It is a cyclic number.

It is not a de Polignac number, because 66481517 - 2⁴ = 66481501 is a prime.

It is a Chen prime.

It is equal to p_3922994 and since 66481517 and 3922994 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66481507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33240758 + 33240759.

It is an arithmetic number, because the mean of its divisors is an integer number (33240759).

Almost surely, 2^66481517 is an apocalyptic number.

It is an amenable number.

66481517 is a deficient number, since it is larger than the sum of its proper divisors (1).

66481517 is an equidigital number, since it uses as much as digits as its factorization.

66481517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 38.

The square root of 66481517 is about 8153.6198709530. The cubic root of 66481517 is about 405.1044124432.

The spelling of 66481517 in words is "sixty-six million, four hundred eighty-one thousand, five hundred seventeen".