12921691 has 8 divisors (see below), whose sum is σ = 13826000. Its totient is φ = 12039840.

The previous prime is 12921679. The next prime is 12921763. The reversal of 12921691 is 19612921.

12921691 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 12921691 - 2⁹ = 12921179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12921611) 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 7 ways as a sum of consecutive naturals, for example, 4416 + ... + 6733.

It is an arithmetic number, because the mean of its divisors is an integer number (1728250).

Almost surely, 2^12921691 is an apocalyptic number.

12921691 is a deficient number, since it is larger than the sum of its proper divisors (904309).

12921691 is a wasteful number, since it uses less digits than its factorization.

12921691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11229.

The product of its digits is 1944, while the sum is 31.

The square root of 12921691 is about 3594.6753678184. The cubic root of 12921691 is about 234.6603876681.

The spelling of 12921691 in words is "twelve million, nine hundred twenty-one thousand, six hundred ninety-one".