1664691078960 has 480 divisors, whose sum is σ = 6909577758720. Its totient is φ = 349758646272.

The previous prime is 1664691078929. The next prime is 1664691078961. The reversal of 1664691078960 is 698701964661.

1664691078960 is a `hidden beast` number, since 1 + 6 + 6 + 469 + 10 + 78 + 96 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (1664691078961) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 15606127 + ... + 15712433.

It is an arithmetic number, because the mean of its divisors is an integer number (14394953664).

Almost surely, 2^{1664691078960} is an apocalyptic number.

1664691078960 is a gapful number since it is divisible by the number (10) 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 1664691078960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3454788879360).

1664691078960 is an abundant number, since it is smaller than the sum of its proper divisors (5244886679760).

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

1664691078960 is a wasteful number, since it uses less digits than its factorization.

1664691078960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106585 (or 106576 counting only the distinct ones).

The product of its (nonzero) digits is 23514624, while the sum is 63.

The spelling of 1664691078960 in words is "one trillion, six hundred sixty-four billion, six hundred ninety-one million, seventy-eight thousand, nine hundred sixty".