21320235 has 24 divisors (see below), whose sum is σ = 37481184. Its totient is φ = 11208960.

The previous prime is 21320213. The next prime is 21320239. The reversal of 21320235 is 53202312.

It is not a de Polignac number, because 21320235 - 2⁵ = 21320203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21320239) 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 23 ways as a sum of consecutive naturals, for example, 142 + ... + 6531.

It is an arithmetic number, because the mean of its divisors is an integer number (1561716).

Almost surely, 2^21320235 is an apocalyptic number.

21320235 is a deficient number, since it is larger than the sum of its proper divisors (16160949).

21320235 is a wasteful number, since it uses less digits than its factorization.

21320235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6755 (or 6752 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21320235 is about 4617.3839996258. The cubic root of 21320235 is about 277.2877363875.

Adding to 21320235 its reverse (53202312), we get a palindrome (74522547).

The spelling of 21320235 in words is "twenty-one million, three hundred twenty thousand, two hundred thirty-five".