12561780 has 96 divisors (see below), whose sum is σ = 43868160. Its totient is φ = 2609280.

The previous prime is 12561751. The next prime is 12561799. The reversal of 12561780 is 8716521.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3261 + ... + 5979.

It is an arithmetic number, because the mean of its divisors is an integer number (456960).

Almost surely, 2^12561780 is an apocalyptic number.

12561780 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 12561780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21934080).

12561780 is an abundant number, since it is smaller than the sum of its proper divisors (31306380).

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

12561780 is a wasteful number, since it uses less digits than its factorization.

12561780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2749 (or 2747 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 12561780 is about 3544.2601484654. The cubic root of 12561780 is about 232.4611566511.

The spelling of 12561780 in words is "twelve million, five hundred sixty-one thousand, seven hundred eighty".