1661560100500 has 96 divisors (see below), whose sum is σ = 3792816518400. Its totient is φ = 634687574400.

The previous prime is 1661560100449. The next prime is 1661560100509. The reversal of 1661560100500 is 50010651661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661560100509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6931651 + ... + 7167349.

It is an arithmetic number, because the mean of its divisors is an integer number (39508505400).

Almost surely, 2^{1661560100500} is an apocalyptic number.

1661560100500 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 1661560100500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1896408259200).

1661560100500 is an abundant number, since it is smaller than the sum of its proper divisors (2131256417900).

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

1661560100500 is a wasteful number, since it uses less digits than its factorization.

1661560100500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236354 (or 236342 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 31.

The spelling of 1661560100500 in words is "one trillion, six hundred sixty-one billion, five hundred sixty million, one hundred thousand, five hundred".