12120400 has 60 divisors (see below), whose sum is σ = 29456572. Its totient is φ = 4792320.

The previous prime is 12120391. The next prime is 12120401. The reversal of 12120400 is 402121.

It can be written as a sum of positive squares in 6 ways, for example, as 1700416 + 10419984 = 1304^2 + 3228^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12120401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62704 + ... + 62896.

Almost surely, 2^12120400 is an apocalyptic number.

12120400 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 12120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14728286).

12120400 is an abundant number, since it is smaller than the sum of its proper divisors (17336172).

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

12120400 is a wasteful number, since it uses less digits than its factorization.

12120400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 12120400 is about 3481.4364851308. The cubic root of 12120400 is about 229.7059885313.

Adding to 12120400 its reverse (402121), we get a palindrome (12522521).

The spelling of 12120400 in words is "twelve million, one hundred twenty thousand, four hundred".