21210211100 has 72 divisors (see below), whose sum is σ = 52175462640. Its totient is φ = 7419271680.

The previous prime is 21210211097. The next prime is 21210211103. The reversal of 21210211100 is 111201212.

It is an interprime number because it is at equal distance from previous prime (21210211097) and next prime (21210211103).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210211103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 404657 + ... + 454056.

Almost surely, 2^21210211100 is an apocalyptic number.

21210211100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210211100 is an abundant number, since it is smaller than the sum of its proper divisors (30965251540).

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

21210211100 is a wasteful number, since it uses less digits than its factorization.

21210211100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 858759 (or 858752 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21210211100 its reverse (111201212), we get a palindrome (21321412312).

The spelling of 21210211100 in words is "twenty-one billion, two hundred ten million, two hundred eleven thousand, one hundred".