12780811 has 4 divisors (see below), whose sum is σ = 12789000. Its totient is φ = 12772624.

The previous prime is 12780809. The next prime is 12780827. The reversal of 12780811 is 11808721.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 11808721 = 2791 ⋅4231.

It is a cyclic number.

It is not a de Polignac number, because 12780811 - 2¹ = 12780809 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12780811.

It is not an unprimeable number, because it can be changed into a prime (12780871) 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, 946 + ... + 5143.

It is an arithmetic number, because the mean of its divisors is an integer number (3197250).

Almost surely, 2^12780811 is an apocalyptic number.

12780811 is a deficient number, since it is larger than the sum of its proper divisors (8189).

12780811 is an equidigital number, since it uses as much as digits as its factorization.

12780811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8188.

The product of its (nonzero) digits is 896, while the sum is 28.

The square root of 12780811 is about 3575.0260138914. The cubic root of 12780811 is about 233.8044668942.

The spelling of 12780811 in words is "twelve million, seven hundred eighty thousand, eight hundred eleven".