12721256329 has 4 divisors (see below), whose sum is σ = 12844763776. Its totient is φ = 12597748884.

The previous prime is 12721256311. The next prime is 12721256351. The reversal of 12721256329 is 92365212721.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12721256329 - 2¹⁹ = 12720732041 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12721256291 and 12721256300.

It is not an unprimeable number, because it can be changed into a prime (12721256129) 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, 61753569 + ... + 61753774.

It is an arithmetic number, because the mean of its divisors is an integer number (3211190944).

Almost surely, 2^12721256329 is an apocalyptic number.

It is an amenable number.

12721256329 is a deficient number, since it is larger than the sum of its proper divisors (123507447).

12721256329 is a wasteful number, since it uses less digits than its factorization.

12721256329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123507446.

The product of its digits is 90720, while the sum is 40.

The spelling of 12721256329 in words is "twelve billion, seven hundred twenty-one million, two hundred fifty-six thousand, three hundred twenty-nine".