2557421 has 4 divisors (see below), whose sum is σ = 2582844. Its totient is φ = 2532000.

The previous prime is 2557417. The next prime is 2557433. The reversal of 2557421 is 1247552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2292196 + 265225 = 1514^2 + 515^2 .

It is a cyclic number.

It is not a de Polignac number, because 2557421 - 2² = 2557417 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 (2557441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12560 + ... + 12761.

It is an arithmetic number, because the mean of its divisors is an integer number (645711).

2^2557421 is an apocalyptic number.

It is an amenable number.

2557421 is a deficient number, since it is larger than the sum of its proper divisors (25423).

2557421 is a wasteful number, since it uses less digits than its factorization.

2557421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25422.

The product of its digits is 2800, while the sum is 26.

The square root of 2557421 is about 1599.1938594179. The cubic root of 2557421 is about 136.7521225079.

The spelling of 2557421 in words is "two million, five hundred fifty-seven thousand, four hundred twenty-one".