1668720801810 has 16 divisors (see below), whose sum is σ = 4004929924416. Its totient is φ = 444992213808.

The previous prime is 1668720801763. The next prime is 1668720801901. The reversal of 1668720801810 is 181080278661.

It is a happy number.

It is a super-2 number, since 2×1668720801810² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1668720801810.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27812013334 + ... + 27812013393.

It is an arithmetic number, because the mean of its divisors is an integer number (250308120276).

Almost surely, 2^{1668720801810} is an apocalyptic number.

1668720801810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1668720801810 is an abundant number, since it is smaller than the sum of its proper divisors (2336209122606).

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

1668720801810 is a wasteful number, since it uses less digits than its factorization.

1668720801810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55624026737.

The product of its (nonzero) digits is 258048, while the sum is 48.

The spelling of 1668720801810 in words is "one trillion, six hundred sixty-eight billion, seven hundred twenty million, eight hundred one thousand, eight hundred ten".