21372353 has 2 divisors, whose sum is σ = 21372354. Its totient is φ = 21372352.

The previous prime is 21372343. The next prime is 21372367. The reversal of 21372353 is 35327312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16096144 + 5276209 = 4012^2 + 2297^2 .

It is a cyclic number.

It is not a de Polignac number, because 21372353 - 2⁶ = 21372289 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21372343) 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 as a sum of consecutive naturals, namely, 10686176 + 10686177.

It is an arithmetic number, because the mean of its divisors is an integer number (10686177).

Almost surely, 2^21372353 is an apocalyptic number.

It is an amenable number.

21372353 is a deficient number, since it is larger than the sum of its proper divisors (1).

21372353 is an equidigital number, since it uses as much as digits as its factorization.

21372353 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 26.

The square root of 21372353 is about 4623.0242266291. The cubic root of 21372353 is about 277.5134987887.

Adding to 21372353 its reverse (35327312), we get a palindrome (56699665).

The spelling of 21372353 in words is "twenty-one million, three hundred seventy-two thousand, three hundred fifty-three".