19661871900 has 288 divisors, whose sum is σ = 67117704192. Its totient is φ = 4390092800.

The previous prime is 19661871877. The next prime is 19661871913. The reversal of 19661871900 is 917816691.

It is a super-2 number, since 2×19661871900² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19661871900.

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, 2632972 + ... + 2640428.

It is an arithmetic number, because the mean of its divisors is an integer number (233047584).

Almost surely, 2^19661871900 is an apocalyptic number.

19661871900 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 19661871900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33558852096).

19661871900 is an abundant number, since it is smaller than the sum of its proper divisors (47455832292).

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

19661871900 is a wasteful number, since it uses less digits than its factorization.

19661871900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7549 (or 7542 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 48.

The spelling of 19661871900 in words is "nineteen billion, six hundred sixty-one million, eight hundred seventy-one thousand, nine hundred".