1668778056 has 192 divisors, whose sum is σ = 5312736000. Its totient is φ = 467752320.

The previous prime is 1668778043. The next prime is 1668778079. The reversal of 1668778056 is 6508778661.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1668777993 and 1668778011.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 645775 + ... + 648353.

It is an arithmetic number, because the mean of its divisors is an integer number (27670500).

Almost surely, 2^1668778056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1668778056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2656368000).

1668778056 is an abundant number, since it is smaller than the sum of its proper divisors (3643957944).

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

1668778056 is a wasteful number, since it uses less digits than its factorization.

1668778056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2664 (or 2657 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The square root of 1668778056 is about 40850.6799943404. The cubic root of 1668778056 is about 1186.1315559975.

The spelling of 1668778056 in words is "one billion, six hundred sixty-eight million, seven hundred seventy-eight thousand, fifty-six".