21020222 has 4 divisors (see below), whose sum is σ = 31530336. Its totient is φ = 10510110.

The previous prime is 21020161. The next prime is 21020227. The reversal of 21020222 is 22202012.

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

It is a super-3 number, since 3×21020222³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255054 + ... + 5255057.

It is an arithmetic number, because the mean of its divisors is an integer number (7882584).

Almost surely, 2^21020222 is an apocalyptic number.

21020222 is a deficient number, since it is larger than the sum of its proper divisors (10510114).

21020222 is a wasteful number, since it uses less digits than its factorization.

21020222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10510113.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 21020222 is about 4584.7815651348. The cubic root of 21020222 is about 275.9809463147.

Adding to 21020222 its reverse (22202012), we get a palindrome (43222234).

The spelling of 21020222 in words is "twenty-one million, twenty thousand, two hundred twenty-two".