66211689393897 has 4 divisors (see below), whose sum is σ = 88282252525200. Its totient is φ = 44141126262596.

The previous prime is 66211689393851. The next prime is 66211689393901. The reversal of 66211689393897 is 79839398611266.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66211689393897 - 2¹⁶ = 66211689328361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66211689393197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11035281565647 + ... + 11035281565652.

It is an arithmetic number, because the mean of its divisors is an integer number (22070563131300).

Almost surely, 2^{66211689393897} is an apocalyptic number.

It is an amenable number.

66211689393897 is a deficient number, since it is larger than the sum of its proper divisors (22070563131303).

66211689393897 is a wasteful number, since it uses less digits than its factorization.

66211689393897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22070563131302.

The product of its digits is 1269789696, while the sum is 78.

The spelling of 66211689393897 in words is "sixty-six trillion, two hundred eleven billion, six hundred eighty-nine million, three hundred ninety-three thousand, eight hundred ninety-seven".