128145221656 has 8 divisors (see below), whose sum is σ = 240272290620. Its totient is φ = 64072610824.

The previous prime is 128145221641. The next prime is 128145221657. The reversal of 128145221656 is 656122541821.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128145221657) 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 as a sum of consecutive naturals, namely, 8009076346 + ... + 8009076361.

Almost surely, 2^128145221656 is an apocalyptic number.

It is an amenable number.

128145221656 is a deficient number, since it is larger than the sum of its proper divisors (112127068964).

128145221656 is a wasteful number, since it uses less digits than its factorization.

128145221656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16018152713 (or 16018152709 counting only the distinct ones).

The product of its digits is 230400, while the sum is 43.

The spelling of 128145221656 in words is "one hundred twenty-eight billion, one hundred forty-five million, two hundred twenty-one thousand, six hundred fifty-six".