21675238 has 64 divisors (see below), whose sum is σ = 40824000. Its totient is φ = 8515584.

The previous prime is 21675211. The next prime is 21675239. The reversal of 21675238 is 83257612.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21675239) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 243498 + ... + 243586.

It is an arithmetic number, because the mean of its divisors is an integer number (637875).

Almost surely, 2^21675238 is an apocalyptic number.

21675238 is a deficient number, since it is larger than the sum of its proper divisors (19148762).

21675238 is a wasteful number, since it uses less digits than its factorization.

21675238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169.

The product of its digits is 20160, while the sum is 34.

The square root of 21675238 is about 4655.6672991098. The cubic root of 21675238 is about 278.8183107266.

The spelling of 21675238 in words is "twenty-one million, six hundred seventy-five thousand, two hundred thirty-eight".