21623353 has 2 divisors, whose sum is σ = 21623354. Its totient is φ = 21623352.

The previous prime is 21623347. The next prime is 21623363. The reversal of 21623353 is 35332612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19954089 + 1669264 = 4467^2 + 1292^2 .

It is a cyclic number.

It is not a de Polignac number, because 21623353 - 2⁵ = 21623321 is a prime.

It is not a weakly prime, because it can be changed into another prime (21623363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10811676 + 10811677.

It is an arithmetic number, because the mean of its divisors is an integer number (10811677).

Almost surely, 2^21623353 is an apocalyptic number.

It is an amenable number.

21623353 is a deficient number, since it is larger than the sum of its proper divisors (1).

21623353 is an equidigital number, since it uses as much as digits as its factorization.

21623353 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 25.

The square root of 21623353 is about 4650.0917195255. The cubic root of 21623353 is about 278.5956596311.

Adding to 21623353 its reverse (35332612), we get a palindrome (56955965).

The spelling of 21623353 in words is "twenty-one million, six hundred twenty-three thousand, three hundred fifty-three".