12405780 has 72 divisors (see below), whose sum is σ = 38571624. Its totient is φ = 3227520.

The previous prime is 12405779. The next prime is 12405793. The reversal of 12405780 is 8750421.

It can be written as a sum of positive squares in 4 ways, for example, as 7817616 + 4588164 = 2796^2 + 2142^2 .

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 302560 + ... + 302600.

It is an arithmetic number, because the mean of its divisors is an integer number (535717).

Almost surely, 2^12405780 is an apocalyptic number.

12405780 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 12405780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19285812).

12405780 is an abundant number, since it is smaller than the sum of its proper divisors (26165844).

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

12405780 is an equidigital number, since it uses as much as digits as its factorization.

12405780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 12405780 is about 3522.1839815660. The cubic root of 12405780 is about 231.4948631047.

The spelling of 12405780 in words is "twelve million, four hundred five thousand, seven hundred eighty".