21233123121 has 32 divisors (see below), whose sum is σ = 32770096128. Its totient is φ = 11978424000.

The previous prime is 21233123101. The next prime is 21233123129. The reversal of 21233123121 is 12132133212.

It is not a de Polignac number, because 21233123121 - 2⁶ = 21233123057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21233123129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 642246 + ... + 674496.

It is an arithmetic number, because the mean of its divisors is an integer number (1024065504).

Almost surely, 2^21233123121 is an apocalyptic number.

21233123121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21233123121 is a deficient number, since it is larger than the sum of its proper divisors (11536973007).

21233123121 is a wasteful number, since it uses less digits than its factorization.

21233123121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32661.

The product of its digits is 432, while the sum is 21.

Adding to 21233123121 its reverse (12132133212), we get a palindrome (33365256333).

The spelling of 21233123121 in words is "twenty-one billion, two hundred thirty-three million, one hundred twenty-three thousand, one hundred twenty-one".