21121100010100 has 18 divisors (see below), whose sum is σ = 45832787022134. Its totient is φ = 8448440004000.

The previous prime is 21121100010083. The next prime is 21121100010133. The reversal of 21121100010100 is 101000112112.

21121100010100 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 6530334924304 + 14590765085796 = 2555452^2 + 3819786^2 .

It is a super-2 number, since 2×21121100010100² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

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 5 ways as a sum of consecutive naturals, for example, 105605499951 + ... + 105605500150.

Almost surely, 2^{21121100010100} is an apocalyptic number.

21121100010100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121100010100 is an abundant number, since it is smaller than the sum of its proper divisors (24711687012034).

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

21121100010100 is a wasteful number, since it uses less digits than its factorization.

21121100010100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211211000115 (or 211211000108 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21121100010100 its reverse (101000112112), we get a palindrome (21222100122212).

The spelling of 21121100010100 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred million, ten thousand, one hundred".