21242526 has 8 divisors (see below), whose sum is σ = 42485064. Its totient is φ = 7080840.

The previous prime is 21242521. The next prime is 21242527. The reversal of 21242526 is 62524212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

21242526 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21242496 and 21242505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242521) 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, 1770205 + ... + 1770216.

It is an arithmetic number, because the mean of its divisors is an integer number (5310633).

Almost surely, 2^21242526 is an apocalyptic number.

21242526 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21242526 is a wasteful number, since it uses less digits than its factorization.

21242526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3540426.

The product of its digits is 1920, while the sum is 24.

The square root of 21242526 is about 4608.9614882314. The cubic root of 21242526 is about 276.9504357704.

Adding to 21242526 its reverse (62524212), we get a palindrome (83766738).

The spelling of 21242526 in words is "twenty-one million, two hundred forty-two thousand, five hundred twenty-six".