12400221440 has 144 divisors (see below), whose sum is σ = 30802851072. Its totient is φ = 4778975232.

The previous prime is 12400221347. The next prime is 12400221443. The reversal of 12400221440 is 4412200421.

It is a super-2 number, since 2×12400221440² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12400221443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5066297 + ... + 5068743.

It is an arithmetic number, because the mean of its divisors is an integer number (213908688).

Almost surely, 2^12400221440 is an apocalyptic number.

12400221440 is a gapful number since it is divisible by the number (10) 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 12400221440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15401425536).

12400221440 is an abundant number, since it is smaller than the sum of its proper divisors (18402629632).

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

12400221440 is a wasteful number, since it uses less digits than its factorization.

12400221440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2612 (or 2598 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 12400221440 its reverse (4412200421), we get a palindrome (16812421861).

The spelling of 12400221440 in words is "twelve billion, four hundred million, two hundred twenty-one thousand, four hundred forty".