21268238 has 16 divisors (see below), whose sum is σ = 33401376. Its totient is φ = 10137600.

The previous prime is 21268231. The next prime is 21268249. The reversal of 21268238 is 83286212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21268231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17870 + ... + 19022.

It is an arithmetic number, because the mean of its divisors is an integer number (2087586).

Almost surely, 2^21268238 is an apocalyptic number.

21268238 is a deficient number, since it is larger than the sum of its proper divisors (12133138).

21268238 is a wasteful number, since it uses less digits than its factorization.

21268238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1579.

The product of its digits is 9216, while the sum is 32.

The square root of 21268238 is about 4611.7499932238. The cubic root of 21268238 is about 277.0621311884.

The spelling of 21268238 in words is "twenty-one million, two hundred sixty-eight thousand, two hundred thirty-eight".