21245336 has 32 divisors (see below), whose sum is σ = 46158240. Its totient is φ = 8978688.

The previous prime is 21245317. The next prime is 21245347. The reversal of 21245336 is 63354212.

It is a congruent number.

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, 1490 + ... + 6686.

It is an arithmetic number, because the mean of its divisors is an integer number (1442445).

Almost surely, 2^21245336 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21245336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23079120).

21245336 is an abundant number, since it is smaller than the sum of its proper divisors (24912904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21245336 is a wasteful number, since it uses less digits than its factorization.

21245336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5283 (or 5279 counting only the distinct ones).

The product of its digits is 4320, while the sum is 26.

The square root of 21245336 is about 4609.2663190577. The cubic root of 21245336 is about 276.9626470678.

Adding to 21245336 its reverse (63354212), we get a palindrome (84599548).

The spelling of 21245336 in words is "twenty-one million, two hundred forty-five thousand, three hundred thirty-six".