66665580283891 has 2 divisors, whose sum is σ = 66665580283892. Its totient is φ = 66665580283890.

The previous prime is 66665580283787. The next prime is 66665580283901. The reversal of 66665580283891 is 19838208556666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66665580283891 is a prime.

It is not a weakly prime, because it can be changed into another prime (69665580283891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33332790141945 + 33332790141946.

It is an arithmetic number, because the mean of its divisors is an integer number (33332790141946).

Almost surely, 2^{66665580283891} is an apocalyptic number.

66665580283891 is a deficient number, since it is larger than the sum of its proper divisors (1).

66665580283891 is an equidigital number, since it uses as much as digits as its factorization.

66665580283891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 895795200, while the sum is 73.

The spelling of 66665580283891 in words is "sixty-six trillion, six hundred sixty-five billion, five hundred eighty million, two hundred eighty-three thousand, eight hundred ninety-one".