21111033312 has 72 divisors (see below), whose sum is σ = 60117004584. Its totient is φ = 7027340544.

The previous prime is 21111033311. The next prime is 21111033341. The reversal of 21111033312 is 21333011112.

21111033312 is a `hidden beast` number, since 211 + 110 + 33 + 312 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111033311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 161103 + ... + 261105.

It is an arithmetic number, because the mean of its divisors is an integer number (834958397).

Almost surely, 2^21111033312 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 21111033312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30058502292).

21111033312 is an abundant number, since it is smaller than the sum of its proper divisors (39005971272).

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

21111033312 is a wasteful number, since it uses less digits than its factorization.

21111033312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100752 (or 100741 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21111033312 its reverse (21333011112), we get a palindrome (42444044424).

The spelling of 21111033312 in words is "twenty-one billion, one hundred eleven million, thirty-three thousand, three hundred twelve".