12021321440 has 24 divisors (see below), whose sum is σ = 28400372280. Its totient is φ = 4808528512.

The previous prime is 12021321439. The next prime is 12021321443. The reversal of 12021321440 is 4412312021.

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 (12021321443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37566470 + ... + 37566789.

It is an arithmetic number, because the mean of its divisors is an integer number (1183348845).

Almost surely, 2^12021321440 is an apocalyptic number.

12021321440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12021321440 is an abundant number, since it is smaller than the sum of its proper divisors (16379050840).

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

12021321440 is an equidigital number, since it uses as much as digits as its factorization.

12021321440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75133274 (or 75133266 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 12021321440 its reverse (4412312021), we get a palindrome (16433633461).

The spelling of 12021321440 in words is "twelve billion, twenty-one million, three hundred twenty-one thousand, four hundred forty".