21123321311212 has 48 divisors (see below), whose sum is σ = 38324242317312. Its totient is φ = 10176594416640.

The previous prime is 21123321311203. The next prime is 21123321311219. The reversal of 21123321311212 is 21211312332112.

It is not an unprimeable number, because it can be changed into a prime (21123321311219) 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, 27017463 + ... + 27788305.

It is an arithmetic number, because the mean of its divisors is an integer number (798421714944).

Almost surely, 2^{21123321311212} is an apocalyptic number.

It is an amenable number.

21123321311212 is a deficient number, since it is larger than the sum of its proper divisors (17200921006100).

21123321311212 is a wasteful number, since it uses less digits than its factorization.

21123321311212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771838 (or 771836 counting only the distinct ones).

The product of its digits is 864, while the sum is 25.

Adding to 21123321311212 its reverse (21211312332112), we get a palindrome (42334633643324).

The spelling of 21123321311212 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred twenty-one million, three hundred eleven thousand, two hundred twelve".