66161551011649 has 2 divisors, whose sum is σ = 66161551011650. Its totient is φ = 66161551011648.

The previous prime is 66161551011583. The next prime is 66161551011719. The reversal of 66161551011649 is 94611015516166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66050973480625 + 110577531024 = 8127175^2 + 332532^2 .

It is a cyclic number.

It is not a de Polignac number, because 66161551011649 - 2¹⁷ = 66161550880577 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66161551011596 and 66161551011605.

It is not a weakly prime, because it can be changed into another prime (66161551011949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33080775505824 + 33080775505825.

It is an arithmetic number, because the mean of its divisors is an integer number (33080775505825).

Almost surely, 2^{66161551011649} is an apocalyptic number.

It is an amenable number.

66161551011649 is a deficient number, since it is larger than the sum of its proper divisors (1).

66161551011649 is an equidigital number, since it uses as much as digits as its factorization.

66161551011649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1166400, while the sum is 52.

The spelling of 66161551011649 in words is "sixty-six trillion, one hundred sixty-one billion, five hundred fifty-one million, eleven thousand, six hundred forty-nine".