21122254 has 4 divisors (see below), whose sum is σ = 31683384. Its totient is φ = 10561126.

The previous prime is 21122251. The next prime is 21122267. The reversal of 21122254 is 45222112.

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

It is a super-2 number, since 2×21122254² = 892299228081032, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5280562 + ... + 5280565.

It is an arithmetic number, because the mean of its divisors is an integer number (7920846).

Almost surely, 2^21122254 is an apocalyptic number.

21122254 is a deficient number, since it is larger than the sum of its proper divisors (10561130).

21122254 is a wasteful number, since it uses less digits than its factorization.

21122254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10561129.

The product of its digits is 320, while the sum is 19.

The square root of 21122254 is about 4595.8953425856. The cubic root of 21122254 is about 276.4267622433.

Adding to 21122254 its reverse (45222112), we get a palindrome (66344366).

The spelling of 21122254 in words is "twenty-one million, one hundred twenty-two thousand, two hundred fifty-four".