1668981295872 has 864 divisors, whose sum is σ = 5568513350400. Its totient is φ = 476098560000.

The previous prime is 1668981295823. The next prime is 1668981295873. The reversal of 1668981295872 is 2785921898661.

1668981295872 is a `hidden beast` number, since 16 + 6 + 8 + 9 + 8 + 1 + 29 + 587 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 1668981295872.

It is not an unprimeable number, because it can be changed into a prime (1668981295873) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6649327747 + ... + 6649327997.

It is an arithmetic number, because the mean of its divisors is an integer number (6445038600).

Almost surely, 2^{1668981295872} is an apocalyptic number.

1668981295872 is a gapful number since it is divisible by the number (12) 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 1668981295872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2784256675200).

1668981295872 is an abundant number, since it is smaller than the sum of its proper divisors (3899532054528).

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

1668981295872 is a wasteful number, since it uses less digits than its factorization.

1668981295872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505 (or 488 counting only the distinct ones).

The product of its digits is 209018880, while the sum is 72.

The spelling of 1668981295872 in words is "one trillion, six hundred sixty-eight billion, nine hundred eighty-one million, two hundred ninety-five thousand, eight hundred seventy-two".