21122221202100 has 108 divisors (see below), whose sum is σ = 67995791951724. Its totient is φ = 5480360087040.

The previous prime is 21122221202081. The next prime is 21122221202101. The reversal of 21122221202100 is 120212222112.

It is a happy number.

21122221202100 is a `hidden beast` number, since 2 + 112 + 222 + 120 + 210 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 4299393956004 + 16822827246096 = 2073498^2 + 4101564^2 .

It is a super-2 number, since 2×21122221202100² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122221202101) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 317117169 + ... + 317183768.

Almost surely, 2^{21122221202100} is an apocalyptic number.

21122221202100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122221202100 is an abundant number, since it is smaller than the sum of its proper divisors (46873570749624).

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

21122221202100 is a wasteful number, since it uses less digits than its factorization.

21122221202100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 634300994 (or 634300984 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21122221202100 its reverse (120212222112), we get a palindrome (21242433424212).

The spelling of 21122221202100 in words is "twenty-one trillion, one hundred twenty-two billion, two hundred twenty-one million, two hundred two thousand, one hundred".