21245733 has 48 divisors (see below), whose sum is σ = 34856640. Its totient is φ = 12877056.

The previous prime is 21245729. The next prime is 21245737. The reversal of 21245733 is 33754212.

It is an interprime number because it is at equal distance from previous prime (21245729) and next prime (21245737).

It is not a de Polignac number, because 21245733 - 2² = 21245729 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21245697 and 21245706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21245737) 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 47 ways as a sum of consecutive naturals, for example, 152778 + ... + 152916.

It is an arithmetic number, because the mean of its divisors is an integer number (726180).

Almost surely, 2^21245733 is an apocalyptic number.

It is an amenable number.

21245733 is a deficient number, since it is larger than the sum of its proper divisors (13610907).

21245733 is a wasteful number, since it uses less digits than its factorization.

21245733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 196 counting only the distinct ones).

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

The square root of 21245733 is about 4609.3093842787. The cubic root of 21245733 is about 276.9643722070.

Adding to 21245733 its reverse (33754212), we get a palindrome (54999945).

The spelling of 21245733 in words is "twenty-one million, two hundred forty-five thousand, seven hundred thirty-three".