1921859116656 has 320 divisors, whose sum is σ = 5570081587200. Its totient is φ = 568400716800.

The previous prime is 1921859116591. The next prime is 1921859116717. The reversal of 1921859116656 is 6566119581291.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1921859116656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 199793415 + ... + 199803033.

It is an arithmetic number, because the mean of its divisors is an integer number (17406504960).

Almost surely, 2^{1921859116656} is an apocalyptic number.

1921859116656 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 1921859116656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2785040793600).

1921859116656 is an abundant number, since it is smaller than the sum of its proper divisors (3648222470544).

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

1921859116656 is a wasteful number, since it uses less digits than its factorization.

1921859116656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9908 (or 9902 counting only the distinct ones).

The product of its digits is 6998400, while the sum is 60.

The spelling of 1921859116656 in words is "one trillion, nine hundred twenty-one billion, eight hundred fifty-nine million, one hundred sixteen thousand, six hundred fifty-six".