66535817977 has 2 divisors, whose sum is σ = 66535817978. Its totient is φ = 66535817976.

The previous prime is 66535817879. The next prime is 66535818001. The reversal of 66535817977 is 77971853566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65927751696 + 608066281 = 256764^2 + 24659^2 .

It is a cyclic number.

It is not a de Polignac number, because 66535817977 - 2⁷ = 66535817849 is a prime.

It is not a weakly prime, because it can be changed into another prime (66535817177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33267908988 + 33267908989.

It is an arithmetic number, because the mean of its divisors is an integer number (33267908989).

Almost surely, 2^66535817977 is an apocalyptic number.

It is an amenable number.

66535817977 is a deficient number, since it is larger than the sum of its proper divisors (1).

66535817977 is an equidigital number, since it uses as much as digits as its factorization.

66535817977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 66679200, while the sum is 64.

The spelling of 66535817977 in words is "sixty-six billion, five hundred thirty-five million, eight hundred seventeen thousand, nine hundred seventy-seven".