12739945 has 4 divisors (see below), whose sum is σ = 15287940. Its totient is φ = 10191952.

The previous prime is 12739943. The next prime is 12739973. The reversal of 12739945 is 54993721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2474329 + 10265616 = 1573^2 + 3204^2 .

It is a cyclic number.

It is not a de Polignac number, because 12739945 - 2¹ = 12739943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12739898 and 12739907.

It is not an unprimeable number, because it can be changed into a prime (12739943) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1273990 + ... + 1273999.

It is an arithmetic number, because the mean of its divisors is an integer number (3821985).

Almost surely, 2^12739945 is an apocalyptic number.

It is an amenable number.

12739945 is a deficient number, since it is larger than the sum of its proper divisors (2547995).

12739945 is an equidigital number, since it uses as much as digits as its factorization.

12739945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2547994.

The product of its digits is 68040, while the sum is 40.

The square root of 12739945 is about 3569.3059549442. The cubic root of 12739945 is about 233.5550081553. Note that the first 3 decimals are identical.

The spelling of 12739945 in words is "twelve million, seven hundred thirty-nine thousand, nine hundred forty-five".