21122223 has 8 divisors (see below), whose sum is σ = 28762368. Its totient is φ = 13781784.

The previous prime is 21122221. The next prime is 21122251. The reversal of 21122223 is 32222112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21122223 - 2¹ = 21122221 is a prime.

It is a super-2 number, since 2×21122223² = 892296608923458, 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, 74761 + ... + 75042.

It is an arithmetic number, because the mean of its divisors is an integer number (3595296).

Almost surely, 2^21122223 is an apocalyptic number.

21122223 is a deficient number, since it is larger than the sum of its proper divisors (7640145).

21122223 is a wasteful number, since it uses less digits than its factorization.

21122223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149853.

The product of its digits is 96, while the sum is 15.

The square root of 21122223 is about 4595.8919700097. The cubic root of 21122223 is about 276.4266270110.

Adding to 21122223 its reverse (32222112), we get a palindrome (53344335).

The spelling of 21122223 in words is "twenty-one million, one hundred twenty-two thousand, two hundred twenty-three".