21113113212 has 96 divisors (see below), whose sum is σ = 60477580800. Its totient is φ = 6335721216.

The previous prime is 21113113201. The next prime is 21113113267. The reversal of 21113113212 is 21231131112.

21113113212 is a `hidden beast` number, since 21 + 11 + 311 + 321 + 2 = 666.

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 a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 207762 + ... + 292217.

It is an arithmetic number, because the mean of its divisors is an integer number (629974800).

Almost surely, 2^21113113212 is an apocalyptic number.

It is an amenable number.

21113113212 is an abundant number, since it is smaller than the sum of its proper divisors (39364467588).

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

21113113212 is a wasteful number, since it uses less digits than its factorization.

21113113212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500032 (or 500024 counting only the distinct ones).

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

Adding to 21113113212 its reverse (21231131112), we get a palindrome (42344244324).

The spelling of 21113113212 in words is "twenty-one billion, one hundred thirteen million, one hundred thirteen thousand, two hundred twelve".