66731288989 has 2 divisors, whose sum is σ = 66731288990. Its totient is φ = 66731288988.

The previous prime is 66731288891. The next prime is 66731289007. The reversal of 66731288989 is 98988213766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66327881764 + 403407225 = 257542^2 + 20085^2 .

It is a cyclic number.

It is not a de Polignac number, because 66731288989 - 2¹⁷ = 66731157917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66731288089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33365644494 + 33365644495.

It is an arithmetic number, because the mean of its divisors is an integer number (33365644495).

Almost surely, 2^66731288989 is an apocalyptic number.

It is an amenable number.

66731288989 is a deficient number, since it is larger than the sum of its proper divisors (1).

66731288989 is an equidigital number, since it uses as much as digits as its factorization.

66731288989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62705664, while the sum is 67.

The spelling of 66731288989 in words is "sixty-six billion, seven hundred thirty-one million, two hundred eighty-eight thousand, nine hundred eighty-nine".