66512989 has 2 divisors, whose sum is σ = 66512990. Its totient is φ = 66512988.

The previous prime is 66512951. The next prime is 66513017. The reversal of 66512989 is 98921566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58644964 + 7868025 = 7658^2 + 2805^2 .

It is a cyclic number.

It is not a de Polignac number, because 66512989 - 2⁹ = 66512477 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66512909) 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, 33256494 + 33256495.

It is an arithmetic number, because the mean of its divisors is an integer number (33256495).

Almost surely, 2^66512989 is an apocalyptic number.

It is an amenable number.

66512989 is a deficient number, since it is larger than the sum of its proper divisors (1).

66512989 is an equidigital number, since it uses as much as digits as its factorization.

66512989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 46.

The square root of 66512989 is about 8155.5495829527. The cubic root of 66512989 is about 405.1683271237.

The spelling of 66512989 in words is "sixty-six million, five hundred twelve thousand, nine hundred eighty-nine".