21912122 has 16 divisors (see below), whose sum is σ = 33809832. Its totient is φ = 10644480.

The previous prime is 21912101. The next prime is 21912157. The reversal of 21912122 is 22121912.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 13623481 + 8288641 = 3691^2 + 2879^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21912094 and 21912103.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 28568 + ... + 29324.

Almost surely, 2^21912122 is an apocalyptic number.

21912122 is a deficient number, since it is larger than the sum of its proper divisors (11897710).

21912122 is a wasteful number, since it uses less digits than its factorization.

With its successor (21912123) it forms an eRAP, since the sums of their prime factors are consecutive (1153 and 1154).

21912122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1153.

The product of its digits is 144, while the sum is 20.

The square root of 21912122 is about 4681.0385599779. The cubic root of 21912122 is about 279.8303479088.

The spelling of 21912122 in words is "twenty-one million, nine hundred twelve thousand, one hundred twenty-two".