12720892609 has 4 divisors (see below), whose sum is σ = 12721166640. Its totient is φ = 12720618580.

The previous prime is 12720892579. The next prime is 12720892621. The reversal of 12720892609 is 90629802721.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90629802721 = 51637 ⋅1755133.

It is a cyclic number.

It is not a de Polignac number, because 12720892609 - 2¹⁹ = 12720368321 is a prime.

It is a super-2 number, since 2×12720892609² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12720892649) 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, 48187 + ... + 166624.

It is an arithmetic number, because the mean of its divisors is an integer number (3180291660).

Almost surely, 2^12720892609 is an apocalyptic number.

It is an amenable number.

12720892609 is a deficient number, since it is larger than the sum of its proper divisors (274031).

12720892609 is an equidigital number, since it uses as much as digits as its factorization.

12720892609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274030.

The product of its (nonzero) digits is 217728, while the sum is 46.

The spelling of 12720892609 in words is "twelve billion, seven hundred twenty million, eight hundred ninety-two thousand, six hundred nine".