2581421 has 4 divisors (see below), whose sum is σ = 2586144. Its totient is φ = 2576700.

The previous prime is 2581417. The next prime is 2581429. The reversal of 2581421 is 1241852.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2581421 - 2² = 2581417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581429) 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 3 ways as a sum of consecutive naturals, for example, 1415 + ... + 2676.

It is an arithmetic number, because the mean of its divisors is an integer number (646536).

2^2581421 is an apocalyptic number.

It is an amenable number.

2581421 is a deficient number, since it is larger than the sum of its proper divisors (4723).

2581421 is an equidigital number, since it uses as much as digits as its factorization.

2581421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4722.

The product of its digits is 640, while the sum is 23.

The square root of 2581421 is about 1606.6801175094. The cubic root of 2581421 is about 137.1785726156.

The spelling of 2581421 in words is "two million, five hundred eighty-one thousand, four hundred twenty-one".