21221221023123 has 16 divisors (see below), whose sum is σ = 31290069357696. Its totient is φ = 12685163250240.

The previous prime is 21221221023109. The next prime is 21221221023173. The reversal of 21221221023123 is 32132012212212.

It is not a de Polignac number, because 21221221023123 - 2¹² = 21221221019027 is a prime.

It is a super-3 number, since 3×21221221023123³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21221221023093 and 21221221023102.

It is not an unprimeable number, because it can be changed into a prime (21221221023173) 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, 4404568165 + ... + 4404572982.

It is an arithmetic number, because the mean of its divisors is an integer number (1955629334856).

Almost surely, 2^{21221221023123} is an apocalyptic number.

21221221023123 is a deficient number, since it is larger than the sum of its proper divisors (10068848334573).

21221221023123 is a wasteful number, since it uses less digits than its factorization.

21221221023123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8809141234.

The product of its (nonzero) digits is 1152, while the sum is 24.

Adding to 21221221023123 its reverse (32132012212212), we get a palindrome (53353233235335).

The spelling of 21221221023123 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-one million, twenty-three thousand, one hundred twenty-three".