12781109 has 12 divisors (see below), whose sum is σ = 14320908. Its totient is φ = 11394240.

The previous prime is 12781103. The next prime is 12781117. The reversal of 12781109 is 90118721.

It can be written as a sum of positive squares in 2 ways, for example, as 9284209 + 3496900 = 3047^2 + 1870^2 .

It is a de Polignac number, because none of the positive numbers 2^k-12781109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12781103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5417 + ... + 7409.

It is an arithmetic number, because the mean of its divisors is an integer number (1193409).

Almost surely, 2^12781109 is an apocalyptic number.

It is an amenable number.

12781109 is a deficient number, since it is larger than the sum of its proper divisors (1539799).

12781109 is a wasteful number, since it uses less digits than its factorization.

12781109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2068 (or 2057 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 12781109 is about 3575.0676916668. The cubic root of 12781109 is about 233.8062840243.

The spelling of 12781109 in words is "twelve million, seven hundred eighty-one thousand, one hundred nine".