21122228 has 24 divisors (see below), whose sum is σ = 39517632. Its totient is φ = 9843584.

The previous prime is 21122221. The next prime is 21122251. The reversal of 21122228 is 82222112.

It is a happy number.

It is a super-2 number, since 2×21122228² = 892297031367968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122221) 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, 5825 + ... + 8727.

It is an arithmetic number, because the mean of its divisors is an integer number (1646568).

Almost surely, 2^21122228 is an apocalyptic number.

It is an amenable number.

21122228 is a deficient number, since it is larger than the sum of its proper divisors (18395404).

21122228 is a wasteful number, since it uses less digits than its factorization.

21122228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3031 (or 3029 counting only the distinct ones).

The product of its digits is 256, while the sum is 20.

The square root of 21122228 is about 4595.8925139738. The cubic root of 21122228 is about 276.4266488227.

The spelling of 21122228 in words is "twenty-one million, one hundred twenty-two thousand, two hundred twenty-eight".