21124873 has 8 divisors (see below), whose sum is σ = 26337600. Its totient is φ = 16460880.

The previous prime is 21124871. The next prime is 21124877. The reversal of 21124873 is 37842112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21124873 - 2¹ = 21124871 is a prime.

It is a super-2 number, since 2×21124873² = 892520518532258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137098 + ... + 137251.

It is an arithmetic number, because the mean of its divisors is an integer number (3292200).

Almost surely, 2^21124873 is an apocalyptic number.

It is an amenable number.

21124873 is a deficient number, since it is larger than the sum of its proper divisors (5212727).

21124873 is a wasteful number, since it uses less digits than its factorization.

21124873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274367.

The product of its digits is 2688, while the sum is 28.

The square root of 21124873 is about 4596.1802619131. The cubic root of 21124873 is about 276.4381867149.

Adding to 21124873 its reverse (37842112), we get a palindrome (58966985).

The spelling of 21124873 in words is "twenty-one million, one hundred twenty-four thousand, eight hundred seventy-three".