12280391 has 4 divisors (see below), whose sum is σ = 12288984. Its totient is φ = 12271800.

The previous prime is 12280379. The next prime is 12280399. The reversal of 12280391 is 19308221.

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: 19308221 = 131 ⋅147391.

It is a cyclic number.

It is not a de Polignac number, because 12280391 - 2¹⁸ = 12018247 is a prime.

It is a super-2 number, since 2×12280391² = 301616006225762, which contains 22 as substring.

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 12280391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12280399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1580 + ... + 5201.

It is an arithmetic number, because the mean of its divisors is an integer number (3072246).

Almost surely, 2^12280391 is an apocalyptic number.

12280391 is a deficient number, since it is larger than the sum of its proper divisors (8593).

12280391 is an equidigital number, since it uses as much as digits as its factorization.

12280391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8592.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 12280391 is about 3504.3388820147. The cubic root of 12280391 is about 230.7122908721.

The spelling of 12280391 in words is "twelve million, two hundred eighty thousand, three hundred ninety-one".