21223118 has 16 divisors (see below), whose sum is σ = 36793440. Its totient is φ = 8992896.

The previous prime is 21223093. The next prime is 21223141. The reversal of 21223118 is 81132212.

It is a self number, because there is not a number n which added to its sum of digits gives 21223118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7271 + ... + 9762.

It is an arithmetic number, because the mean of its divisors is an integer number (2299590).

Almost surely, 2^21223118 is an apocalyptic number.

21223118 is a deficient number, since it is larger than the sum of its proper divisors (15570322).

21223118 is a wasteful number, since it uses less digits than its factorization.

21223118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17131.

The product of its digits is 192, while the sum is 20.

The square root of 21223118 is about 4606.8555436436. The cubic root of 21223118 is about 276.8660658318.

The spelling of 21223118 in words is "twenty-one million, two hundred twenty-three thousand, one hundred eighteen".