66557396089 has 2 divisors, whose sum is σ = 66557396090. Its totient is φ = 66557396088.

The previous prime is 66557396083. The next prime is 66557396119. The reversal of 66557396089 is 98069375566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51759890064 + 14797506025 = 227508^2 + 121645^2 .

It is a cyclic number.

It is not a de Polignac number, because 66557396089 - 2⁹ = 66557395577 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66557396089.

It is not a weakly prime, because it can be changed into another prime (66557396083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33278698044 + 33278698045.

It is an arithmetic number, because the mean of its divisors is an integer number (33278698045).

Almost surely, 2^66557396089 is an apocalyptic number.

It is an amenable number.

66557396089 is a deficient number, since it is larger than the sum of its proper divisors (1).

66557396089 is an equidigital number, since it uses as much as digits as its factorization.

66557396089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 73483200, while the sum is 64.

The spelling of 66557396089 in words is "sixty-six billion, five hundred fifty-seven million, three hundred ninety-six thousand, eighty-nine".