21122265 has 8 divisors (see below), whose sum is σ = 33795648. Its totient is φ = 11265200.

The previous prime is 21122251. The next prime is 21122267. The reversal of 21122265 is 56222112.

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 21122265 - 2⁶ = 21122201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21122267) 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 in 7 ways as a sum of consecutive naturals, for example, 704061 + ... + 704090.

It is an arithmetic number, because the mean of its divisors is an integer number (4224456).

Almost surely, 2^21122265 is an apocalyptic number.

It is an amenable number.

21122265 is a deficient number, since it is larger than the sum of its proper divisors (12673383).

21122265 is a wasteful number, since it uses less digits than its factorization.

21122265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1408159.

The product of its digits is 480, while the sum is 21.

The square root of 21122265 is about 4595.8965393055. The cubic root of 21122265 is about 276.4268102289.

Adding to 21122265 its reverse (56222112), we get a palindrome (77344377).

The spelling of 21122265 in words is "twenty-one million, one hundred twenty-two thousand, two hundred sixty-five".