21233455 has 4 divisors (see below), whose sum is σ = 25480152. Its totient is φ = 16986760.

The previous prime is 21233453. The next prime is 21233461. The reversal of 21233455 is 55433212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21233455 - 2¹ = 21233453 is a prime.

It is a super-2 number, since 2×21233455² = 901719222474050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2123341 + ... + 2123350.

It is an arithmetic number, because the mean of its divisors is an integer number (6370038).

Almost surely, 2^21233455 is an apocalyptic number.

21233455 is a deficient number, since it is larger than the sum of its proper divisors (4246697).

21233455 is an equidigital number, since it uses as much as digits as its factorization.

21233455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4246696.

The product of its digits is 3600, while the sum is 25.

The square root of 21233455 is about 4607.9773219928. The cubic root of 21233455 is about 276.9110089609.

Adding to 21233455 its reverse (55433212), we get a palindrome (76666667).

The spelling of 21233455 in words is "twenty-one million, two hundred thirty-three thousand, four hundred fifty-five".