21455323 has 4 divisors (see below), whose sum is σ = 21954328. Its totient is φ = 20956320.

The previous prime is 21455321. The next prime is 21455327. The reversal of 21455323 is 32355412.

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

It is a cyclic number.

It is not a de Polignac number, because 21455323 - 2¹ = 21455321 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21455321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 249438 + ... + 249523.

It is an arithmetic number, because the mean of its divisors is an integer number (5488582).

Almost surely, 2^21455323 is an apocalyptic number.

21455323 is a deficient number, since it is larger than the sum of its proper divisors (499005).

21455323 is an equidigital number, since it uses as much as digits as its factorization.

21455323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499004.

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

The square root of 21455323 is about 4631.9890975692. The cubic root of 21455323 is about 277.8721484806.

The spelling of 21455323 in words is "twenty-one million, four hundred fifty-five thousand, three hundred twenty-three".