66155513 has 2 divisors, whose sum is σ = 66155514. Its totient is φ = 66155512.

The previous prime is 66155497. The next prime is 66155527. The reversal of 66155513 is 31555166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34199104 + 31956409 = 5848^2 + 5653^2 .

It is a cyclic number.

It is not a de Polignac number, because 66155513 - 2⁴ = 66155497 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66155513.

It is not a weakly prime, because it can be changed into another prime (66155533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33077756 + 33077757.

It is an arithmetic number, because the mean of its divisors is an integer number (33077757).

Almost surely, 2^66155513 is an apocalyptic number.

It is an amenable number.

66155513 is a deficient number, since it is larger than the sum of its proper divisors (1).

66155513 is an equidigital number, since it uses as much as digits as its factorization.

66155513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13500, while the sum is 32.

The square root of 66155513 is about 8133.6039367552. The cubic root of 66155513 is about 404.4411598378.

The spelling of 66155513 in words is "sixty-six million, one hundred fifty-five thousand, five hundred thirteen".