21330351 has 16 divisors (see below), whose sum is σ = 36115200. Its totient is φ = 12188664.

The previous prime is 21330347. The next prime is 21330367. The reversal of 21330351 is 15303312.

It is not a de Polignac number, because 21330351 - 2² = 21330347 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56241 + ... + 56618.

It is an arithmetic number, because the mean of its divisors is an integer number (2257200).

Almost surely, 2^21330351 is an apocalyptic number.

21330351 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21330351 is a deficient number, since it is larger than the sum of its proper divisors (14784849).

21330351 is a wasteful number, since it uses less digits than its factorization.

21330351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112875 (or 112869 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 18.

The square root of 21330351 is about 4618.4792951793. The cubic root of 21330351 is about 277.3315851727.

Adding to 21330351 its reverse (15303312), we get a palindrome (36633663).

The spelling of 21330351 in words is "twenty-one million, three hundred thirty thousand, three hundred fifty-one".