12561940 has 12 divisors (see below), whose sum is σ = 26380116. Its totient is φ = 5024768.

The previous prime is 12561931. The next prime is 12561947. The reversal of 12561940 is 4916521.

It can be written as a sum of positive squares in 2 ways, for example, as 7739524 + 4822416 = 2782^2 + 2196^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12561899 and 12561908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 314029 + ... + 314068.

It is an arithmetic number, because the mean of its divisors is an integer number (2198343).

Almost surely, 2^12561940 is an apocalyptic number.

12561940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12561940 is an abundant number, since it is smaller than the sum of its proper divisors (13818176).

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

12561940 is a wasteful number, since it uses less digits than its factorization.

12561940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628106 (or 628104 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 12561940 is about 3544.2827201001. The cubic root of 12561940 is about 232.4621436033.

The spelling of 12561940 in words is "twelve million, five hundred sixty-one thousand, nine hundred forty".