21121213332123 has 16 divisors (see below), whose sum is σ = 31307043361440. Its totient is φ = 14073448263552.

The previous prime is 21121213332091. The next prime is 21121213332179. The reversal of 21121213332123 is 32123331212112.

21121213332123 is a `hidden beast` number, since 2 + 1 + 121 + 213 + 3 + 321 + 2 + 3 = 666.

It is not a de Polignac number, because 21121213332123 - 2⁵ = 21121213332091 is a prime.

It is a super-2 number, since 2×21121213332123² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21121213339123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 204409186 + ... + 204512487.

It is an arithmetic number, because the mean of its divisors is an integer number (1956690210090).

Almost surely, 2^{21121213332123} is an apocalyptic number.

21121213332123 is a deficient number, since it is larger than the sum of its proper divisors (10185830029317).

21121213332123 is a wasteful number, since it uses less digits than its factorization.

21121213332123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408923595 (or 408923589 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

Adding to 21121213332123 its reverse (32123331212112), we get a palindrome (53244544544235).

The spelling of 21121213332123 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred thirteen million, three hundred thirty-two thousand, one hundred twenty-three".