21025222 has 4 divisors (see below), whose sum is σ = 31537836. Its totient is φ = 10512610.

The previous prime is 21025217. The next prime is 21025273. The reversal of 21025222 is 22252012.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21025196 and 21025205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5256304 + ... + 5256307.

It is an arithmetic number, because the mean of its divisors is an integer number (7884459).

Almost surely, 2^21025222 is an apocalyptic number.

21025222 is a deficient number, since it is larger than the sum of its proper divisors (10512614).

21025222 is a wasteful number, since it uses less digits than its factorization.

21025222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10512613.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 21025222 is about 4585.3268149610. The cubic root of 21025222 is about 276.0028267581.

Adding to 21025222 its reverse (22252012), we get a palindrome (43277234).

The spelling of 21025222 in words is "twenty-one million, twenty-five thousand, two hundred twenty-two".