2421857 has 4 divisors (see below), whose sum is σ = 2451120. Its totient is φ = 2392596.

The previous prime is 2421847. The next prime is 2421893. The reversal of 2421857 is 7581242.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7581242 = 2 ⋅3790621.

It is a cyclic number.

It is not a de Polignac number, because 2421857 - 2⁴ = 2421841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2421817) 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, 14507 + ... + 14672.

It is an arithmetic number, because the mean of its divisors is an integer number (612780).

2^2421857 is an apocalyptic number.

It is an amenable number.

2421857 is a deficient number, since it is larger than the sum of its proper divisors (29263).

2421857 is an equidigital number, since it uses as much as digits as its factorization.

2421857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29262.

The product of its digits is 4480, while the sum is 29.

The square root of 2421857 is about 1556.2316665587. The cubic root of 2421857 is about 134.2918011749.

The spelling of 2421857 in words is "two million, four hundred twenty-one thousand, eight hundred fifty-seven".