12451921 has 2 divisors, whose sum is σ = 12451922. Its totient is φ = 12451920.

The previous prime is 12451919. The next prime is 12451931. The reversal of 12451921 is 12915421.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8294400 + 4157521 = 2880^2 + 2039^2 .

It is a cyclic number.

It is not a de Polignac number, because 12451921 - 2¹ = 12451919 is a prime.

Together with 12451919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12451931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6225960 + 6225961.

It is an arithmetic number, because the mean of its divisors is an integer number (6225961).

Almost surely, 2^12451921 is an apocalyptic number.

It is an amenable number.

12451921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12451921 is an equidigital number, since it uses as much as digits as its factorization.

12451921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 25.

The square root of 12451921 is about 3528.7279577774. The cubic root of 12451921 is about 231.7815087724.

The spelling of 12451921 in words is "twelve million, four hundred fifty-one thousand, nine hundred twenty-one".