66561424265223 has 80 divisors (see below), whose sum is σ = 106854301128960. Its totient is φ = 41197969612800.

The previous prime is 66561424265209. The next prime is 66561424265251. The reversal of 66561424265223 is 32256242416566.

66561424265223 is a `hidden beast` number, since 6 + 6 + 5 + 6 + 142 + 426 + 52 + 23 = 666.

It is not a de Polignac number, because 66561424265223 - 2⁸ = 66561424264967 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66561424265223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66561424965223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 8521543 + ... + 14343623.

It is an arithmetic number, because the mean of its divisors is an integer number (1335678764112).

Almost surely, 2^{66561424265223} is an apocalyptic number.

66561424265223 is a deficient number, since it is larger than the sum of its proper divisors (40292876863737).

66561424265223 is a wasteful number, since it uses less digits than its factorization.

66561424265223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5822310 (or 5822301 counting only the distinct ones).

The product of its digits is 24883200, while the sum is 54.

The spelling of 66561424265223 in words is "sixty-six trillion, five hundred sixty-one billion, four hundred twenty-four million, two hundred sixty-five thousand, two hundred twenty-three".