12021043540 has 24 divisors (see below), whose sum is σ = 27539118432. Its totient is φ = 4371288480.

The previous prime is 12021043523. The next prime is 12021043571. The reversal of 12021043540 is 4534012021.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27320334 + ... + 27320773.

It is an arithmetic number, because the mean of its divisors is an integer number (1147463268).

Almost surely, 2^12021043540 is an apocalyptic number.

12021043540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12021043540 is an abundant number, since it is smaller than the sum of its proper divisors (15518074892).

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

12021043540 is a wasteful number, since it uses less digits than its factorization.

12021043540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54641127 (or 54641125 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

Adding to 12021043540 its reverse (4534012021), we get a palindrome (16555055561).

The spelling of 12021043540 in words is "twelve billion, twenty-one million, forty-three thousand, five hundred forty".