1665426868560 has 480 divisors, whose sum is σ = 7024262918400. Its totient is φ = 351386090496.

The previous prime is 1665426868549. The next prime is 1665426868603. The reversal of 1665426868560 is 658686245661.

It is a happy number.

1665426868560 is a `hidden beast` number, since 1 + 6 + 6 + 5 + 4 + 2 + 6 + 8 + 68 + 560 = 666.

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

It is a congruent number.

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 95 ways as a sum of consecutive naturals, for example, 2951107 + ... + 3469853.

It is an arithmetic number, because the mean of its divisors is an integer number (14633881080).

Almost surely, 2^{1665426868560} is an apocalyptic number.

1665426868560 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 1665426868560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3512131459200).

1665426868560 is an abundant number, since it is smaller than the sum of its proper divisors (5358836049840).

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

1665426868560 is a wasteful number, since it uses less digits than its factorization.

1665426868560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518800 (or 518777 counting only the distinct ones).

The product of its (nonzero) digits is 99532800, while the sum is 63.

The spelling of 1665426868560 in words is "one trillion, six hundred sixty-five billion, four hundred twenty-six million, eight hundred sixty-eight thousand, five hundred sixty".