21103022100 has 144 divisors (see below), whose sum is σ = 63794666880. Its totient is φ = 5375884800.

The previous prime is 21103022089. The next prime is 21103022107. The reversal of 21103022100 is 122030112.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103022107) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7374670 + ... + 7377530.

It is an arithmetic number, because the mean of its divisors is an integer number (443018520).

Almost surely, 2^21103022100 is an apocalyptic number.

21103022100 is a gapful number since it is divisible by the number (20) 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 21103022100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31897333440).

21103022100 is an abundant number, since it is smaller than the sum of its proper divisors (42691644780).

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

21103022100 is a wasteful number, since it uses less digits than its factorization.

21103022100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3970 (or 3963 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21103022100 its reverse (122030112), we get a palindrome (21225052212).

The spelling of 21103022100 in words is "twenty-one billion, one hundred three million, twenty-two thousand, one hundred".