66057221069991 has 32 divisors (see below), whose sum is σ = 103014061152000. Its totient is φ = 41720005533024.

The previous prime is 66057221069969. The next prime is 66057221070013. The reversal of 66057221069991 is 19996012275066.

66057221069991 is a `hidden beast` number, since 6 + 605 + 7 + 2 + 2 + 10 + 6 + 9 + 9 + 9 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (66057221069969) and next prime (66057221070013).

It is not a de Polignac number, because 66057221069991 - 2⁷ = 66057221069863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66057221062991) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71003356 + ... + 71927678.

It is an arithmetic number, because the mean of its divisors is an integer number (3219189411000).

Almost surely, 2^{66057221069991} is an apocalyptic number.

66057221069991 is a deficient number, since it is larger than the sum of its proper divisors (36956840082009).

66057221069991 is a wasteful number, since it uses less digits than its factorization.

66057221069991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063660 (or 1063654 counting only the distinct ones).

The product of its (nonzero) digits is 22044960, while the sum is 63.

The spelling of 66057221069991 in words is "sixty-six trillion, fifty-seven billion, two hundred twenty-one million, sixty-nine thousand, nine hundred ninety-one".