21424534 has 24 divisors (see below), whose sum is σ = 33889104. Its totient is φ = 10155600.

The previous prime is 21424511. The next prime is 21424547. The reversal of 21424534 is 43542412.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21424499 and 21424508.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 136384 + ... + 136540.

It is an arithmetic number, because the mean of its divisors is an integer number (1412046).

Almost surely, 2^21424534 is an apocalyptic number.

21424534 is a deficient number, since it is larger than the sum of its proper divisors (12464570).

21424534 is a wasteful number, since it uses less digits than its factorization.

21424534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292 (or 261 counting only the distinct ones).

The product of its digits is 3840, while the sum is 25.

The square root of 21424534 is about 4628.6643861918. The cubic root of 21424534 is about 277.7391666985.

Adding to 21424534 its reverse (43542412), we get a palindrome (64966946).

The spelling of 21424534 in words is "twenty-one million, four hundred twenty-four thousand, five hundred thirty-four".