21045336 has 32 divisors (see below), whose sum is σ = 56661360. Its totient is φ = 6475392.

The previous prime is 21045319. The next prime is 21045377. The reversal of 21045336 is 63354012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33415 + ... + 34038.

Almost surely, 2^21045336 is an apocalyptic number.

21045336 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21045336 is an abundant number, since it is smaller than the sum of its proper divisors (35616024).

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

21045336 is a wasteful number, since it uses less digits than its factorization.

21045336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67475 (or 67471 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 21045336 is about 4587.5195912388. The cubic root of 21045336 is about 276.0908123767.

Adding to 21045336 its reverse (63354012), we get a palindrome (84399348).

The spelling of 21045336 in words is "twenty-one million, forty-five thousand, three hundred thirty-six".