21121200102123 has 128 divisors (see below), whose sum is σ = 37577405537280. Its totient is φ = 11578457088000.

The previous prime is 21121200102113. The next prime is 21121200102181. The reversal of 21121200102123 is 32120100212112.

It is not a de Polignac number, because 21121200102123 - 2⁶ = 21121200102059 is a prime.

It is a super-2 number, since 2×21121200102123² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121200102096 and 21121200102105.

It is not an unprimeable number, because it can be changed into a prime (21121200102113) by changing a digit.

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 127 ways as a sum of consecutive naturals, for example, 13108183 + ... + 14631023.

It is an arithmetic number, because the mean of its divisors is an integer number (293573480760).

Almost surely, 2^{21121200102123} is an apocalyptic number.

21121200102123 is a deficient number, since it is larger than the sum of its proper divisors (16456205435157).

21121200102123 is a wasteful number, since it uses less digits than its factorization.

21121200102123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1522986 (or 1522980 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21121200102123 its reverse (32120100212112), we get a palindrome (53241300314235).

The spelling of 21121200102123 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred million, one hundred two thousand, one hundred twenty-three".