21126122 has 4 divisors (see below), whose sum is σ = 31689186. Its totient is φ = 10563060.

The previous prime is 21126109. The next prime is 21126169. The reversal of 21126122 is 22162112.

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

It can be written as a sum of positive squares in only one way, i.e., 21077281 + 48841 = 4591^2 + 221^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21126122.

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 as a sum of consecutive naturals, namely, 5281529 + ... + 5281532.

Almost surely, 2^21126122 is an apocalyptic number.

21126122 is a deficient number, since it is larger than the sum of its proper divisors (10563064).

21126122 is a wasteful number, since it uses less digits than its factorization.

21126122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10563063.

The product of its digits is 96, while the sum is 17.

The square root of 21126122 is about 4596.3161336009. The cubic root of 21126122 is about 276.4436347080.

Adding to 21126122 its reverse (22162112), we get a palindrome (43288234).

It can be divided in two parts, 2112612 and 2, that multiplied together give a palindrome (4225224).

The spelling of 21126122 in words is "twenty-one million, one hundred twenty-six thousand, one hundred twenty-two".