21217368 has 16 divisors (see below), whose sum is σ = 53043480. Its totient is φ = 7072448.

The previous prime is 21217367. The next prime is 21217379. The reversal of 21217368 is 86371212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21217367) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 442005 + ... + 442052.

Almost surely, 2^21217368 is an apocalyptic number.

It is an amenable number.

21217368 is an abundant number, since it is smaller than the sum of its proper divisors (31826112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21217368 is a wasteful number, since it uses less digits than its factorization.

21217368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884066 (or 884062 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 21217368 is about 4606.2314314415. The cubic root of 21217368 is about 276.8410597092.

The spelling of 21217368 in words is "twenty-one million, two hundred seventeen thousand, three hundred sixty-eight".