1666853517020 has 12 divisors (see below), whose sum is σ = 3500392385784. Its totient is φ = 666741406800.

The previous prime is 1666853517001. The next prime is 1666853517023. The reversal of 1666853517020 is 207153586661.

It is a self number, because there is not a number n which added to its sum of digits gives 1666853517020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666853517023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41671337906 + ... + 41671337945.

It is an arithmetic number, because the mean of its divisors is an integer number (291699365482).

Almost surely, 2^{1666853517020} is an apocalyptic number.

1666853517020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666853517020 is an abundant number, since it is smaller than the sum of its proper divisors (1833538868764).

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

1666853517020 is a wasteful number, since it uses less digits than its factorization.

1666853517020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83342675860 (or 83342675858 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 50.

The spelling of 1666853517020 in words is "one trillion, six hundred sixty-six billion, eight hundred fifty-three million, five hundred seventeen thousand, twenty".