21144312112 has 80 divisors (see below), whose sum is σ = 51270861312. Its totient is φ = 8206594560.

The previous prime is 21144312097. The next prime is 21144312143. The reversal of 21144312112 is 21121344112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 291388 + ... + 356644.

Almost surely, 2^21144312112 is an apocalyptic number.

21144312112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21144312112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25635430656).

21144312112 is an abundant number, since it is smaller than the sum of its proper divisors (30126549200).

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

21144312112 is a wasteful number, since it uses less digits than its factorization.

21144312112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65546 (or 65540 counting only the distinct ones).

The product of its digits is 384, while the sum is 22.

Adding to 21144312112 its reverse (21121344112), we get a palindrome (42265656224).

The spelling of 21144312112 in words is "twenty-one billion, one hundred forty-four million, three hundred twelve thousand, one hundred twelve".