1664219875968 has 256 divisors, whose sum is σ = 5460224179200. Its totient is φ = 495548928000.

The previous prime is 1664219875949. The next prime is 1664219876021. The reversal of 1664219875968 is 8695789124661.

1664219875968 is a `hidden beast` number, since 1 + 6 + 6 + 4 + 21 + 9 + 8 + 7 + 596 + 8 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 1664219875896 and 1664219875905.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 795318 + ... + 1990218.

It is an arithmetic number, because the mean of its divisors is an integer number (21329000700).

Almost surely, 2^{1664219875968} is an apocalyptic number.

1664219875968 is a gapful number since it is divisible by the number (18) 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 1664219875968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2730112089600).

1664219875968 is an abundant number, since it is smaller than the sum of its proper divisors (3796004303232).

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

1664219875968 is a wasteful number, since it uses less digits than its factorization.

1664219875968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194968 (or 1194950 counting only the distinct ones).

The product of its digits is 313528320, while the sum is 72.

The spelling of 1664219875968 in words is "one trillion, six hundred sixty-four billion, two hundred nineteen million, eight hundred seventy-five thousand, nine hundred sixty-eight".