12961649 has 4 divisors (see below), whose sum is σ = 12970560. Its totient is φ = 12952740.

The previous prime is 12961621. The next prime is 12961657. The reversal of 12961649 is 94616921.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94616921 = 7 ⋅13516703.

It is a cyclic number.

It is not a de Polignac number, because 12961649 - 2⁸ = 12961393 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12961349) 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, 1709 + ... + 5370.

It is an arithmetic number, because the mean of its divisors is an integer number (3242640).

Almost surely, 2^12961649 is an apocalyptic number.

It is an amenable number.

12961649 is a deficient number, since it is larger than the sum of its proper divisors (8911).

12961649 is an equidigital number, since it uses as much as digits as its factorization.

12961649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8910.

The product of its digits is 23328, while the sum is 38.

The square root of 12961649 is about 3600.2290204930. The cubic root of 12961649 is about 234.9020204191.

The spelling of 12961649 in words is "twelve million, nine hundred sixty-one thousand, six hundred forty-nine".