12700728781 has 8 divisors (see below), whose sum is σ = 14482279224. Its totient is φ = 11034117120.

The previous prime is 12700728773. The next prime is 12700728787. The reversal of 12700728781 is 18782700721.

It can be written as a sum of positive squares in 4 ways, for example, as 891559881 + 11809168900 = 29859^2 + 108670^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12700728781 - 2³ = 12700728773 is a prime.

It is a super-2 number, since 2×12700728781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12700728787) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28734460 + ... + 28734901.

It is an arithmetic number, because the mean of its divisors is an integer number (1810284903).

Almost surely, 2^12700728781 is an apocalyptic number.

It is an amenable number.

12700728781 is a deficient number, since it is larger than the sum of its proper divisors (1781550443).

12700728781 is a wasteful number, since it uses less digits than its factorization.

12700728781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57469391.

The product of its (nonzero) digits is 87808, while the sum is 43.

The spelling of 12700728781 in words is "twelve billion, seven hundred million, seven hundred twenty-eight thousand, seven hundred eighty-one".