21323110212 has 216 divisors, whose sum is σ = 58506704256. Its totient is φ = 6536775168.

The previous prime is 21323110147. The next prime is 21323110223. The reversal of 21323110212 is 21201132312.

21323110212 is a `hidden beast` number, since 21 + 323 + 110 + 212 = 666.

It is a super-2 number, since 2×21323110212² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 239585464 + ... + 239585552.

Almost surely, 2^21323110212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21323110212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29253352128).

21323110212 is an abundant number, since it is smaller than the sum of its proper divisors (37183594044).

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

21323110212 is a wasteful number, since it uses less digits than its factorization.

21323110212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21323110212 its reverse (21201132312), we get a palindrome (42524242524).

The spelling of 21323110212 in words is "twenty-one billion, three hundred twenty-three million, one hundred ten thousand, two hundred twelve".