2551421 has 2 divisors, whose sum is σ = 2551422. Its totient is φ = 2551420.

The previous prime is 2551403. The next prime is 2551429. The reversal of 2551421 is 1241552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2544025 + 7396 = 1595^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 2551421 - 2⁶ = 2551357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2551393 and 2551402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2551429) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1275710 + 1275711.

It is an arithmetic number, because the mean of its divisors is an integer number (1275711).

2^2551421 is an apocalyptic number.

It is an amenable number.

2551421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2551421 is an equidigital number, since it uses as much as digits as its factorization.

2551421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 400, while the sum is 20.

The square root of 2551421 is about 1597.3168126580. The cubic root of 2551421 is about 136.6450934287.

Adding to 2551421 its reverse (1241552), we get a palindrome (3792973).

The spelling of 2551421 in words is "two million, five hundred fifty-one thousand, four hundred twenty-one".