21122221100 has 18 divisors (see below), whose sum is σ = 45835220004. Its totient is φ = 8448888400.

The previous prime is 21122221037. The next prime is 21122221121. The reversal of 21122221100 is 112222112.

It is a super-2 number, since 2×21122221100² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105611006 + ... + 105611205.

Almost surely, 2^21122221100 is an apocalyptic number.

21122221100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122221100 is an abundant number, since it is smaller than the sum of its proper divisors (24712998904).

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

21122221100 is a wasteful number, since it uses less digits than its factorization.

21122221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211222225 (or 211222218 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21122221100 its reverse (112222112), we get a palindrome (21234443212).

The spelling of 21122221100 in words is "twenty-one billion, one hundred twenty-two million, two hundred twenty-one thousand, one hundred".