66565811287919 has 2 divisors, whose sum is σ = 66565811287920. Its totient is φ = 66565811287918.

The previous prime is 66565811287763. The next prime is 66565811287967. The reversal of 66565811287919 is 91978211856566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66565811287919 - 2⁸ = 66565811287663 is a prime.

It is a super-2 number, since 2×66565811287919² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66565811227919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33282905643959 + 33282905643960.

It is an arithmetic number, because the mean of its divisors is an integer number (33282905643960).

Almost surely, 2^{66565811287919} is an apocalyptic number.

66565811287919 is a deficient number, since it is larger than the sum of its proper divisors (1).

66565811287919 is an equidigital number, since it uses as much as digits as its factorization.

66565811287919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 391910400, while the sum is 74.

The spelling of 66565811287919 in words is "sixty-six trillion, five hundred sixty-five billion, eight hundred eleven million, two hundred eighty-seven thousand, nine hundred nineteen".