66681037 has 2 divisors, whose sum is σ = 66681038. Its totient is φ = 66681036.

The previous prime is 66681011. The next prime is 66681053. The reversal of 66681037 is 73018666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40271716 + 26409321 = 6346^2 + 5139^2 .

It is a cyclic number.

It is not a de Polignac number, because 66681037 - 2⁷ = 66680909 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66680987 and 66681005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66681007) 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, 33340518 + 33340519.

It is an arithmetic number, because the mean of its divisors is an integer number (33340519).

Almost surely, 2^66681037 is an apocalyptic number.

It is an amenable number.

66681037 is a deficient number, since it is larger than the sum of its proper divisors (1).

66681037 is an equidigital number, since it uses as much as digits as its factorization.

66681037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 66681037 is about 8165.8457614628. The cubic root of 66681037 is about 405.5092653685.

The spelling of 66681037 in words is "sixty-six million, six hundred eighty-one thousand, thirty-seven".