11311123212 has 72 divisors (see below), whose sum is σ = 29423826432. Its totient is φ = 3661912800.

The previous prime is 11311123183. The next prime is 11311123223. The reversal of 11311123212 is 21232111311.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 196137 + ... + 247167.

It is an arithmetic number, because the mean of its divisors is an integer number (408664256).

Almost surely, 2^11311123212 is an apocalyptic number.

11311123212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11311123212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14711913216).

11311123212 is an abundant number, since it is smaller than the sum of its proper divisors (18112703220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11311123212 is a wasteful number, since it uses less digits than its factorization.

11311123212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51219 (or 51214 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 11311123212 its reverse (21232111311), we get a palindrome (32543234523).

The spelling of 11311123212 in words is "eleven billion, three hundred eleven million, one hundred twenty-three thousand, two hundred twelve".