21312203112 has 128 divisors (see below), whose sum is σ = 61247491200. Its totient is φ = 6861888000.

The previous prime is 21312203057. The next prime is 21312203131. The reversal of 21312203112 is 21130221312.

21312203112 is a `hidden beast` number, since 2 + 131 + 220 + 311 + 2 = 666.

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 31 ways as a sum of consecutive naturals, for example, 882543 + ... + 906369.

It is an arithmetic number, because the mean of its divisors is an integer number (478496025).

Almost surely, 2^21312203112 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 21312203112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30623745600).

21312203112 is an abundant number, since it is smaller than the sum of its proper divisors (39935288088).

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

21312203112 is a wasteful number, since it uses less digits than its factorization.

21312203112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23984 (or 23974 counting only the distinct ones).

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

Adding to 21312203112 its reverse (21130221312), we get a palindrome (42442424424).

The spelling of 21312203112 in words is "twenty-one billion, three hundred twelve million, two hundred three thousand, one hundred twelve".