21121000021100 has 72 divisors (see below), whose sum is σ = 52382163347808. Its totient is φ = 7241197708800.

The previous prime is 21121000021091. The next prime is 21121000021111. The reversal of 21121000021100 is 112000012112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17397920 + ... + 18572280.

Almost surely, 2^{21121000021100} is an apocalyptic number.

21121000021100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121000021100 is an abundant number, since it is smaller than the sum of its proper divisors (31261163326708).

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

21121000021100 is a wasteful number, since it uses less digits than its factorization.

21121000021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200075 (or 1200068 counting only the distinct ones).

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

Adding to 21121000021100 its reverse (112000012112), we get a palindrome (21233000033212).

The spelling of 21121000021100 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-one thousand, one hundred".