21121020222100 has 36 divisors (see below), whose sum is σ = 46286402160348. Its totient is φ = 8364760480000.

The previous prime is 21121020222091. The next prime is 21121020222143. The reversal of 21121020222100 is 122202012112.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 60392079504 + 21060628142596 = 245748^2 + 4589186^2 .

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 1045584961 + ... + 1045605160.

It is an arithmetic number, because the mean of its divisors is an integer number (1285733393343).

Almost surely, 2^{21121020222100} is an apocalyptic number.

21121020222100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121020222100 is an abundant number, since it is smaller than the sum of its proper divisors (25165381938248).

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

21121020222100 is a wasteful number, since it uses less digits than its factorization.

21121020222100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2091190236 (or 2091190229 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21121020222100 its reverse (122202012112), we get a palindrome (21243222234212).

The spelling of 21121020222100 in words is "twenty-one trillion, one hundred twenty-one billion, twenty million, two hundred twenty-two thousand, one hundred".