66220426640 has 40 divisors (see below), whose sum is σ = 155137802688. Its totient is φ = 26285966720.

The previous prime is 66220426639. The next prime is 66220426661. The reversal of 66220426640 is 4662402266.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 66220426594 and 66220426603.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3148892 + ... + 3169851.

Almost surely, 2^66220426640 is an apocalyptic number.

It is an amenable number.

66220426640 is an abundant number, since it is smaller than the sum of its proper divisors (88917376048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66220426640 is a wasteful number, since it uses less digits than its factorization.

66220426640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6318887 (or 6318881 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 38.

The spelling of 66220426640 in words is "sixty-six billion, two hundred twenty million, four hundred twenty-six thousand, six hundred forty".