21101110100 has 54 divisors (see below), whose sum is σ = 53265243150. Its totient is φ = 7234664640.

The previous prime is 21101110099. The next prime is 21101110207. The reversal of 21101110100 is 101110112.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 101042704 + 21000067396 = 10052^2 + 144914^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2148275 + ... + 2158074.

Almost surely, 2^21101110100 is an apocalyptic number.

21101110100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101110100 is an abundant number, since it is smaller than the sum of its proper divisors (32164133050).

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

21101110100 is a wasteful number, since it uses less digits than its factorization.

21101110100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4306377 (or 4306363 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 8.

Adding to 21101110100 its reverse (101110112), we get a palindrome (21202220212).

The spelling of 21101110100 in words is "twenty-one billion, one hundred one million, one hundred ten thousand, one hundred".