12120556440 has 128 divisors (see below), whose sum is σ = 37083744000. Its totient is φ = 3168281088.

The previous prime is 12120556439. The next prime is 12120556447. The reversal of 12120556440 is 4465502121.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 12120556398 and 12120556407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12120556447) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2681062 + ... + 2685578.

It is an arithmetic number, because the mean of its divisors is an integer number (289716750).

Almost surely, 2^12120556440 is an apocalyptic number.

12120556440 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 12120556440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18541872000).

12120556440 is an abundant number, since it is smaller than the sum of its proper divisors (24963187560).

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

12120556440 is a wasteful number, since it uses less digits than its factorization.

12120556440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4969 (or 4965 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

The spelling of 12120556440 in words is "twelve billion, one hundred twenty million, five hundred fifty-six thousand, four hundred forty".