66550195640 has 16 divisors (see below), whose sum is σ = 149737940280. Its totient is φ = 26620078240.

The previous prime is 66550195633. The next prime is 66550195757. The reversal of 66550195640 is 4659105566.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 831877406 + ... + 831877485.

Almost surely, 2^66550195640 is an apocalyptic number.

It is an amenable number.

66550195640 is an abundant number, since it is smaller than the sum of its proper divisors (83187744640).

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

66550195640 is a wasteful number, since it uses less digits than its factorization.

66550195640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663754902 (or 1663754898 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 47.

The spelling of 66550195640 in words is "sixty-six billion, five hundred fifty million, one hundred ninety-five thousand, six hundred forty".