21100000194 has 288 divisors, whose sum is σ = 62907062400. Its totient is φ = 4959470592.

The previous prime is 21100000157. The next prime is 21100000219. The reversal of 21100000194 is 49100000112.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 143 ways as a sum of consecutive naturals, for example, 10051357 + ... + 10053455.

It is an arithmetic number, because the mean of its divisors is an integer number (218427300).

Almost surely, 2^21100000194 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21100000194, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31453531200).

21100000194 is an abundant number, since it is smaller than the sum of its proper divisors (41807062206).

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

21100000194 is a wasteful number, since it uses less digits than its factorization.

21100000194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2182 (or 2160 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The spelling of 21100000194 in words is "twenty-one billion, one hundred million, one hundred ninety-four", and thus it is an aban number.