66711923509 has 16 divisors (see below), whose sum is σ = 83262162816. Its totient is φ = 51927782400.

The previous prime is 66711923501. The next prime is 66711923519. The reversal of 66711923509 is 90532911766.

It is a cyclic number.

It is not a de Polignac number, because 66711923509 - 2³ = 66711923501 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66711923501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 390172 + ... + 534469.

It is an arithmetic number, because the mean of its divisors is an integer number (5203885176).

Almost surely, 2^66711923509 is an apocalyptic number.

It is an amenable number.

66711923509 is a deficient number, since it is larger than the sum of its proper divisors (16550239307).

66711923509 is a wasteful number, since it uses less digits than its factorization.

66711923509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925596.

The product of its (nonzero) digits is 612360, while the sum is 49.

The spelling of 66711923509 in words is "sixty-six billion, seven hundred eleven million, nine hundred twenty-three thousand, five hundred nine".