24225721 has 4 divisors (see below), whose sum is σ = 26089252. Its totient is φ = 22362192.

The previous prime is 24225689. The next prime is 24225737. The reversal of 24225721 is 12752242.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12752242 = 2 ⋅6376121.

It can be written as a sum of positive squares in 2 ways, for example, as 3111696 + 21114025 = 1764^2 + 4595^2 .

It is a cyclic number.

It is not a de Polignac number, because 24225721 - 2⁵ = 24225689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (24222721) 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, 931746 + ... + 931771.

It is an arithmetic number, because the mean of its divisors is an integer number (6522313).

Almost surely, 2^24225721 is an apocalyptic number.

It is an amenable number.

24225721 is a deficient number, since it is larger than the sum of its proper divisors (1863531).

24225721 is a wasteful number, since it uses less digits than its factorization.

24225721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1863530.

The product of its digits is 2240, while the sum is 25.

The square root of 24225721 is about 4921.9631246079. The cubic root of 24225721 is about 289.3513882931.

Adding to 24225721 its reverse (12752242), we get a palindrome (36977963).

The spelling of 24225721 in words is "twenty-four million, two hundred twenty-five thousand, seven hundred twenty-one".