21121002198 has 96 divisors (see below), whose sum is σ = 49158791136. Its totient is φ = 6530233344.

The previous prime is 21121002187. The next prime is 21121002211. The reversal of 21121002198 is 89120012112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14145940 + ... + 14147432.

It is an arithmetic number, because the mean of its divisors is an integer number (512070741).

Almost surely, 2^21121002198 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121002198, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24579395568).

21121002198 is an abundant number, since it is smaller than the sum of its proper divisors (28037788938).

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

21121002198 is a wasteful number, since it uses less digits than its factorization.

21121002198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2158 (or 2155 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 27.

The spelling of 21121002198 in words is "twenty-one billion, one hundred twenty-one million, two thousand, one hundred ninety-eight".