21122121102100 has 18 divisors (see below), whose sum is σ = 45835002791774. Its totient is φ = 8448848440800.

The previous prime is 21122121102083. The next prime is 21122121102139. The reversal of 21122121102100 is 120112122112.

It can be written as a sum of positive squares in 3 ways, for example, as 138410785296 + 20983710316804 = 372036^2 + 4580798^2 .

It is a super-2 number, since 2×21122121102100² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

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, 105610605411 + ... + 105610605610.

Almost surely, 2^{21122121102100} is an apocalyptic number.

21122121102100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122121102100 is an abundant number, since it is smaller than the sum of its proper divisors (24712881689674).

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

21122121102100 is a wasteful number, since it uses less digits than its factorization.

21122121102100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211221211035 (or 211221211028 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21122121102100 its reverse (120112122112), we get a palindrome (21242233224212).

The spelling of 21122121102100 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred twenty-one million, one hundred two thousand, one hundred".