66681053 has 2 divisors, whose sum is σ = 66681054. Its totient is φ = 66681052.

The previous prime is 66681037. The next prime is 66681059. The reversal of 66681053 is 35018666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63712324 + 2968729 = 7982^2 + 1723^2 .

It is a cyclic number.

It is not a de Polignac number, because 66681053 - 2⁴ = 66681037 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66681059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33340526 + 33340527.

It is an arithmetic number, because the mean of its divisors is an integer number (33340527).

Almost surely, 2^66681053 is an apocalyptic number.

It is an amenable number.

66681053 is a deficient number, since it is larger than the sum of its proper divisors (1).

66681053 is an equidigital number, since it uses as much as digits as its factorization.

66681053 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 66681053 is about 8165.8467411531. The cubic root of 66681053 is about 405.5092978022.

The spelling of 66681053 in words is "sixty-six million, six hundred eighty-one thousand, fifty-three".