21513226 has 8 divisors (see below), whose sum is σ = 36879840. Its totient is φ = 9219948.

The previous prime is 21513209. The next prime is 21513227. The reversal of 21513226 is 62231512.

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

It is a junction number, because it is equal to n+sod(n) for n = 21513197 and 21513206.

It is not an unprimeable number, because it can be changed into a prime (21513227) 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, 768316 + ... + 768343.

It is an arithmetic number, because the mean of its divisors is an integer number (4609980).

Almost surely, 2^21513226 is an apocalyptic number.

21513226 is a deficient number, since it is larger than the sum of its proper divisors (15366614).

21513226 is a wasteful number, since it uses less digits than its factorization.

21513226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1536668.

The product of its digits is 720, while the sum is 22.

The square root of 21513226 is about 4638.2352247380. The cubic root of 21513226 is about 278.1218950291.

Adding to 21513226 its reverse (62231512), we get a palindrome (83744738).

The spelling of 21513226 in words is "twenty-one million, five hundred thirteen thousand, two hundred twenty-six".