21344455 has 8 divisors (see below), whose sum is σ = 27941904. Its totient is φ = 15523200.

The previous prime is 21344447. The next prime is 21344459. The reversal of 21344455 is 55444312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21344455 - 2³ = 21344447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344459) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193986 + ... + 194095.

It is an arithmetic number, because the mean of its divisors is an integer number (3492738).

Almost surely, 2^21344455 is an apocalyptic number.

21344455 is a deficient number, since it is larger than the sum of its proper divisors (6597449).

21344455 is a wasteful number, since it uses less digits than its factorization.

21344455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388097.

The product of its digits is 9600, while the sum is 28.

The square root of 21344455 is about 4620.0059523771. The cubic root of 21344455 is about 277.3926971985.

Adding to 21344455 its reverse (55444312), we get a palindrome (76788767).

The spelling of 21344455 in words is "twenty-one million, three hundred forty-four thousand, four hundred fifty-five".