1656128887 has 8 divisors (see below), whose sum is σ = 1910084000. Its totient is φ = 1406515104.

The previous prime is 1656128819. The next prime is 1656128909. The reversal of 1656128887 is 7888216561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1656128887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1656120887) 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 7 ways as a sum of consecutive naturals, for example, 1084512 + ... + 1086037.

It is an arithmetic number, because the mean of its divisors is an integer number (238760500).

Almost surely, 2^1656128887 is an apocalyptic number.

1656128887 is a deficient number, since it is larger than the sum of its proper divisors (253955113).

1656128887 is a wasteful number, since it uses less digits than its factorization.

1656128887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2170665.

The product of its digits is 1290240, while the sum is 52.

The square root of 1656128887 is about 40695.5634805565. The cubic root of 1656128887 is about 1183.1270327304.

The spelling of 1656128887 in words is "one billion, six hundred fifty-six million, one hundred twenty-eight thousand, eight hundred eighty-seven".