21124265 has 8 divisors (see below), whose sum is σ = 25470528. Its totient is φ = 16818480.

The previous prime is 21124253. The next prime is 21124273. The reversal of 21124265 is 56242112.

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 21124265 - 2¹⁶ = 21058729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21124265.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8957 + ... + 11066.

It is an arithmetic number, because the mean of its divisors is an integer number (3183816).

Almost surely, 2^21124265 is an apocalyptic number.

It is an amenable number.

21124265 is a deficient number, since it is larger than the sum of its proper divisors (4346263).

21124265 is a wasteful number, since it uses less digits than its factorization.

21124265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20239.

The product of its digits is 960, while the sum is 23.

The square root of 21124265 is about 4596.1141195580. The cubic root of 21124265 is about 276.4355346117.

Adding to 21124265 its reverse (56242112), we get a palindrome (77366377).

The spelling of 21124265 in words is "twenty-one million, one hundred twenty-four thousand, two hundred sixty-five".