2421521 has 4 divisors (see below), whose sum is σ = 2425200. Its totient is φ = 2417844.

The previous prime is 2421511. The next prime is 2421527. The reversal of 2421521 is 1251242.

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: 1251242 = 2 ⋅625621.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2421521 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2421521.

It is not an unprimeable number, because it can be changed into a prime (2421527) 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, 551 + ... + 2268.

It is an arithmetic number, because the mean of its divisors is an integer number (606300).

2^2421521 is an apocalyptic number.

It is an amenable number.

2421521 is a deficient number, since it is larger than the sum of its proper divisors (3679).

2421521 is an equidigital number, since it uses as much as digits as its factorization.

2421521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3678.

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

The square root of 2421521 is about 1556.1237097352. The cubic root of 2421521 is about 134.2855904955.

Adding to 2421521 its reverse (1251242), we get a palindrome (3672763).

The spelling of 2421521 in words is "two million, four hundred twenty-one thousand, five hundred twenty-one".