21321320112 has 120 divisors (see below), whose sum is σ = 60590437440. Its totient is φ = 6997985280.

The previous prime is 21321320107. The next prime is 21321320129. The reversal of 21321320112 is 21102312312.

21321320112 is a `hidden beast` number, since 21 + 321 + 320 + 1 + 1 + 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 23 ways as a sum of consecutive naturals, for example, 4513912 + ... + 4518632.

It is an arithmetic number, because the mean of its divisors is an integer number (504920312).

Almost surely, 2^21321320112 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 21321320112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30295218720).

21321320112 is an abundant number, since it is smaller than the sum of its proper divisors (39269117328).

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

21321320112 is a wasteful number, since it uses less digits than its factorization.

21321320112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5211 (or 5202 counting only the distinct ones).

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

Adding to 21321320112 its reverse (21102312312), we get a palindrome (42423632424).

The spelling of 21321320112 in words is "twenty-one billion, three hundred twenty-one million, three hundred twenty thousand, one hundred twelve".