12783440 has 20 divisors (see below), whose sum is σ = 29721684. Its totient is φ = 5113344.

The previous prime is 12783401. The next prime is 12783451. The reversal of 12783440 is 4438721.

It can be written as a sum of positive squares in 2 ways, for example, as 1547536 + 11235904 = 1244^2 + 3352^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79817 + ... + 79976.

Almost surely, 2^12783440 is an apocalyptic number.

12783440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12783440 is an abundant number, since it is smaller than the sum of its proper divisors (16938244).

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

12783440 is a wasteful number, since it uses less digits than its factorization.

12783440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159806 (or 159800 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 12783440 is about 3575.3936846171. The cubic root of 12783440 is about 233.8204969099.

The spelling of 12783440 in words is "twelve million, seven hundred eighty-three thousand, four hundred forty".