1656443778816 has 144 divisors (see below), whose sum is σ = 4517659657728. Its totient is φ = 538492723200.

The previous prime is 1656443778799. The next prime is 1656443778827. The reversal of 1656443778816 is 6188773446561.

It is a congruent number.

It is an unprimeable number.

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, 111680521 + ... + 111695351.

It is an arithmetic number, because the mean of its divisors is an integer number (31372636512).

Almost surely, 2^{1656443778816} is an apocalyptic number.

1656443778816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1656443778816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2258829828864).

1656443778816 is an abundant number, since it is smaller than the sum of its proper divisors (2861215878912).

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

1656443778816 is a wasteful number, since it uses less digits than its factorization.

1656443778816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18438 (or 18424 counting only the distinct ones).

The product of its digits is 162570240, while the sum is 66.

The spelling of 1656443778816 in words is "one trillion, six hundred fifty-six billion, four hundred forty-three million, seven hundred seventy-eight thousand, eight hundred sixteen".