21245337 has 6 divisors (see below), whose sum is σ = 30687722. Its totient is φ = 14163552.

The previous prime is 21245317. The next prime is 21245347. The reversal of 21245337 is 73354212.

21245337 is a `hidden beast` number, since 2 + 124 + 533 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16475481 + 4769856 = 4059^2 + 2184^2 .

It is not a de Polignac number, because 21245337 - 2¹⁴ = 21228953 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 21245337.

It is not an unprimeable number, because it can be changed into a prime (21245317) 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 5 ways as a sum of consecutive naturals, for example, 1180288 + ... + 1180305.

Almost surely, 2^21245337 is an apocalyptic number.

It is an amenable number.

21245337 is a deficient number, since it is larger than the sum of its proper divisors (9442385).

21245337 is a wasteful number, since it uses less digits than its factorization.

21245337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2360599 (or 2360596 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 21245337 is about 4609.2664275349. The cubic root of 21245337 is about 276.9626514133.

Adding to 21245337 its reverse (73354212), we get a palindrome (94599549).

The spelling of 21245337 in words is "twenty-one million, two hundred forty-five thousand, three hundred thirty-seven".