66021564202991 has 2 divisors, whose sum is σ = 66021564202992. Its totient is φ = 66021564202990.

The previous prime is 66021564202949. The next prime is 66021564203003. The reversal of 66021564202991 is 19920246512066.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66021564202991 is a prime.

It is a super-3 number, since 3×66021564202991³ (a number of 42 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66021564202291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33010782101495 + 33010782101496.

It is an arithmetic number, because the mean of its divisors is an integer number (33010782101496).

Almost surely, 2^{66021564202991} is an apocalyptic number.

66021564202991 is a deficient number, since it is larger than the sum of its proper divisors (1).

66021564202991 is an equidigital number, since it uses as much as digits as its factorization.

66021564202991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2799360, while the sum is 53.

The spelling of 66021564202991 in words is "sixty-six trillion, twenty-one billion, five hundred sixty-four million, two hundred two thousand, nine hundred ninety-one".