21311022312 has 192 divisors, whose sum is σ = 61770945600. Its totient is φ = 6626810880.

The previous prime is 21311022277. The next prime is 21311022319. The reversal of 21311022312 is 21322011312.

21311022312 is a `hidden beast` number, since 21 + 311 + 0 + 22 + 312 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21311022319) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6442563 + ... + 6445869.

It is an arithmetic number, because the mean of its divisors is an integer number (321723675).

Almost surely, 2^21311022312 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 21311022312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30885472800).

21311022312 is an abundant number, since it is smaller than the sum of its proper divisors (40459923288).

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

21311022312 is a wasteful number, since it uses less digits than its factorization.

21311022312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3456 (or 3449 counting only the distinct ones).

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

Adding to 21311022312 its reverse (21322011312), we get a palindrome (42633033624).

The spelling of 21311022312 in words is "twenty-one billion, three hundred eleven million, twenty-two thousand, three hundred twelve".