21311223123212 has 12 divisors (see below), whose sum is σ = 40685062326216. Its totient is φ = 9686919601440.

The previous prime is 21311223123209. The next prime is 21311223123217. The reversal of 21311223123212 is 21232132211312.

21311223123212 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (21311223123217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242172989993 + ... + 242172990080.

It is an arithmetic number, because the mean of its divisors is an integer number (3390421860518).

Almost surely, 2^{21311223123212} is an apocalyptic number.

21311223123212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21311223123212 is a deficient number, since it is larger than the sum of its proper divisors (19373839203004).

21311223123212 is a wasteful number, since it uses less digits than its factorization.

21311223123212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484345980088 (or 484345980086 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

Adding to 21311223123212 its reverse (21232132211312), we get a palindrome (42543355334524).

The spelling of 21311223123212 in words is "twenty-one trillion, three hundred eleven billion, two hundred twenty-three million, one hundred twenty-three thousand, two hundred twelve".