21524234 has 4 divisors (see below), whose sum is σ = 32286354. Its totient is φ = 10762116.

The previous prime is 21524231. The next prime is 21524249. The reversal of 21524234 is 43242512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 13712209 + 7812025 = 3703^2 + 2795^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21524231) 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 as a sum of consecutive naturals, namely, 5381057 + ... + 5381060.

Almost surely, 2^21524234 is an apocalyptic number.

21524234 is a deficient number, since it is larger than the sum of its proper divisors (10762120).

21524234 is a wasteful number, since it uses less digits than its factorization.

21524234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10762119.

The product of its digits is 1920, while the sum is 23.

The square root of 21524234 is about 4639.4217312075. The cubic root of 21524234 is about 278.1693238958.

Adding to 21524234 its reverse (43242512), we get a palindrome (64766746).

The spelling of 21524234 in words is "twenty-one million, five hundred twenty-four thousand, two hundred thirty-four".