1666109923620 has 96 divisors (see below), whose sum is σ = 4913663462400. Its totient is φ = 420652808064.

The previous prime is 1666109923613. The next prime is 1666109923813. The reversal of 1666109923620 is 263299016661.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1405641 + ... + 2303919.

It is an arithmetic number, because the mean of its divisors is an integer number (51183994400).

Almost surely, 2^{1666109923620} is an apocalyptic number.

1666109923620 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 1666109923620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2456831731200).

1666109923620 is an abundant number, since it is smaller than the sum of its proper divisors (3247553538780).

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

1666109923620 is a wasteful number, since it uses less digits than its factorization.

1666109923620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899937 (or 899935 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 51.

The spelling of 1666109923620 in words is "one trillion, six hundred sixty-six billion, one hundred nine million, nine hundred twenty-three thousand, six hundred twenty".