66717644012801 has 2 divisors, whose sum is σ = 66717644012802. Its totient is φ = 66717644012800.

The previous prime is 66717644012791. The next prime is 66717644012827. The reversal of 66717644012801 is 10821044671766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64791310983025 + 1926333029776 = 8049305^2 + 1387924^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66717644012801 is a prime.

It is a super-2 number, since 2×66717644012801² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66717644012881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33358822006400 + 33358822006401.

It is an arithmetic number, because the mean of its divisors is an integer number (33358822006401).

Almost surely, 2^{66717644012801} is an apocalyptic number.

It is an amenable number.

66717644012801 is a deficient number, since it is larger than the sum of its proper divisors (1).

66717644012801 is an equidigital number, since it uses as much as digits as its factorization.

66717644012801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2709504, while the sum is 53.

The spelling of 66717644012801 in words is "sixty-six trillion, seven hundred seventeen billion, six hundred forty-four million, twelve thousand, eight hundred one".