21424254 has 16 divisors (see below), whose sum is σ = 42964992. Its totient is φ = 7122008.

The previous prime is 21424253. The next prime is 21424261. The reversal of 21424254 is 45242412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2364 + ... + 6959.

It is an arithmetic number, because the mean of its divisors is an integer number (2685312).

Almost surely, 2^21424254 is an apocalyptic number.

21424254 is an abundant number, since it is smaller than the sum of its proper divisors (21540738).

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

21424254 is a wasteful number, since it uses less digits than its factorization.

21424254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9711.

The product of its digits is 2560, while the sum is 24.

The square root of 21424254 is about 4628.6341397868. The cubic root of 21424254 is about 277.7379567569.

Adding to 21424254 its reverse (45242412), we get a palindrome (66666666).

The spelling of 21424254 in words is "twenty-one million, four hundred twenty-four thousand, two hundred fifty-four".