21118226 has 4 divisors (see below), whose sum is σ = 31677342. Its totient is φ = 10559112.

The previous prime is 21118219. The next prime is 21118247. The reversal of 21118226 is 62281112.

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., 12967201 + 8151025 = 3601^2 + 2855^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5279555 + ... + 5279558.

Almost surely, 2^21118226 is an apocalyptic number.

21118226 is a deficient number, since it is larger than the sum of its proper divisors (10559116).

21118226 is a wasteful number, since it uses less digits than its factorization.

21118226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10559115.

The product of its digits is 384, while the sum is 23.

The square root of 21118226 is about 4595.4571045762. The cubic root of 21118226 is about 276.4091896587.

Adding to 21118226 its reverse (62281112), we get a palindrome (83399338).

The spelling of 21118226 in words is "twenty-one million, one hundred eighteen thousand, two hundred twenty-six".