21434523 has 32 divisors (see below), whose sum is σ = 32313600. Its totient is φ = 12528000.

The previous prime is 21434471. The next prime is 21434531. The reversal of 21434523 is 32543412.

It is not a de Polignac number, because 21434523 - 2¹⁴ = 21418139 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21434493 and 21434502.

It is not an unprimeable number, because it can be changed into a prime (21434123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 196593 + ... + 196701.

It is an arithmetic number, because the mean of its divisors is an integer number (1009800).

Almost surely, 2^21434523 is an apocalyptic number.

21434523 is a deficient number, since it is larger than the sum of its proper divisors (10879077).

21434523 is a wasteful number, since it uses less digits than its factorization.

21434523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283.

The product of its digits is 2880, while the sum is 24.

The square root of 21434523 is about 4629.7432974194. The cubic root of 21434523 is about 277.7823244708.

Adding to 21434523 its reverse (32543412), we get a palindrome (53977935).

Subtracting 21434523 from its reverse (32543412), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 2143 and 4523, that added together give a palindrome (6666).

The spelling of 21434523 in words is "twenty-one million, four hundred thirty-four thousand, five hundred twenty-three".