2451221 has 2 divisors, whose sum is σ = 2451222. Its totient is φ = 2451220.

The previous prime is 2451203. The next prime is 2451223. The reversal of 2451221 is 1221542.

2451221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2283121 + 168100 = 1511^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 2451221 - 2¹⁴ = 2434837 is a prime.

Together with 2451223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2451221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2451223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1225610 + 1225611.

It is an arithmetic number, because the mean of its divisors is an integer number (1225611).

2^2451221 is an apocalyptic number.

It is an amenable number.

2451221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2451221 is an equidigital number, since it uses as much as digits as its factorization.

2451221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 160, while the sum is 17.

The square root of 2451221 is about 1565.6375698098. The cubic root of 2451221 is about 134.8323662327.

Adding to 2451221 its reverse (1221542), we get a palindrome (3672763).

The spelling of 2451221 in words is "two million, four hundred fifty-one thousand, two hundred twenty-one".