21010202100 has 216 divisors, whose sum is σ = 67920652800. Its totient is φ = 5428304640.

The previous prime is 21010202099. The next prime is 21010202107. The reversal of 21010202100 is 120201012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010202107) 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 71 ways as a sum of consecutive naturals, for example, 8756701 + ... + 8759099.

Almost surely, 2^21010202100 is an apocalyptic number.

21010202100 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 21010202100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33960326400).

21010202100 is an abundant number, since it is smaller than the sum of its proper divisors (46910450700).

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

21010202100 is a wasteful number, since it uses less digits than its factorization.

21010202100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2719 (or 2709 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21010202100 its reverse (120201012), we get a palindrome (21130403112).

The spelling of 21010202100 in words is "twenty-one billion, ten million, two hundred two thousand, one hundred".