21000023202123 has 48 divisors (see below), whose sum is σ = 34791836242176. Its totient is φ = 11956773913920.

The previous prime is 21000023202113. The next prime is 21000023202149. The reversal of 21000023202123 is 32120232000012.

It is not a de Polignac number, because 21000023202123 - 2¹² = 21000023198027 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000023202096 and 21000023202105.

It is not an unprimeable number, because it can be changed into a prime (21000023202113) 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 47 ways as a sum of consecutive naturals, for example, 19572013 + ... + 20617073.

It is an arithmetic number, because the mean of its divisors is an integer number (724829921712).

Almost surely, 2^{21000023202123} is an apocalyptic number.

21000023202123 is a deficient number, since it is larger than the sum of its proper divisors (13791813040053).

21000023202123 is a wasteful number, since it uses less digits than its factorization.

21000023202123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046224 (or 1046221 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21000023202123 its reverse (32120232000012), we get a palindrome (53120255202135).

The spelling of 21000023202123 in words is "twenty-one trillion, twenty-three million, two hundred two thousand, one hundred twenty-three".