21504082 has 8 divisors (see below), whose sum is σ = 34153596. Its totient is φ = 10119552.

The previous prime is 21504053. The next prime is 21504083. The reversal of 21504082 is 28040512.

It can be written as a sum of positive squares in 2 ways, for example, as 21335161 + 168921 = 4619^2 + 411^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21504083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 316203 + ... + 316270.

Almost surely, 2^21504082 is an apocalyptic number.

21504082 is a deficient number, since it is larger than the sum of its proper divisors (12649514).

21504082 is a wasteful number, since it uses less digits than its factorization.

21504082 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632492.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 21504082 is about 4637.2494002372. The cubic root of 21504082 is about 278.0824850555.

Adding to 21504082 its reverse (28040512), we get a palindrome (49544594).

The spelling of 21504082 in words is "twenty-one million, five hundred four thousand, eighty-two".