12491921 has 16 divisors (see below), whose sum is σ = 14394240. Its totient is φ = 10750080.

The previous prime is 12491917. The next prime is 12491933. The reversal of 12491921 is 12919421.

It is a cyclic number.

It is not a de Polignac number, because 12491921 - 2² = 12491917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12491971) 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 15 ways as a sum of consecutive naturals, for example, 11750 + ... + 12768.

It is an arithmetic number, because the mean of its divisors is an integer number (899640).

Almost surely, 2^12491921 is an apocalyptic number.

It is an amenable number.

12491921 is a deficient number, since it is larger than the sum of its proper divisors (1902319).

12491921 is a wasteful number, since it uses less digits than its factorization.

12491921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096.

The product of its digits is 1296, while the sum is 29.

The square root of 12491921 is about 3534.3911781239. The cubic root of 12491921 is about 232.0294317100.

The spelling of 12491921 in words is "twelve million, four hundred ninety-one thousand, nine hundred twenty-one".