24540021 has 12 divisors (see below), whose sum is σ = 38669280. Its totient is φ = 14872680.

The previous prime is 24539989. The next prime is 24540031. The reversal of 24540021 is 12004542.

24540021 is a `hidden beast` number, since 245 + 400 + 21 = 666.

It is not a de Polignac number, because 24540021 - 2⁵ = 24539989 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 24539976 and 24540003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (24540031) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 123841 + ... + 124038.

It is an arithmetic number, because the mean of its divisors is an integer number (3222440).

Almost surely, 2^24540021 is an apocalyptic number.

It is an amenable number.

24540021 is a deficient number, since it is larger than the sum of its proper divisors (14129259).

24540021 is a wasteful number, since it uses less digits than its factorization.

24540021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247896 (or 247893 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 24540021 is about 4953.7885501907. The cubic root of 24540021 is about 290.5973458251.

Adding to 24540021 its reverse (12004542), we get a palindrome (36544563).

It can be divided in two parts, 24 and 540021, that added together give a palindrome (540045).

The spelling of 24540021 in words is "twenty-four million, five hundred forty thousand, twenty-one".