21360455 has 4 divisors (see below), whose sum is σ = 25632552. Its totient is φ = 17088360.

The previous prime is 21360439. The next prime is 21360481. The reversal of 21360455 is 55406312.

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

It is not a de Polignac number, because 21360455 - 2⁴ = 21360439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2136041 + ... + 2136050.

It is an arithmetic number, because the mean of its divisors is an integer number (6408138).

Almost surely, 2^21360455 is an apocalyptic number.

21360455 is a deficient number, since it is larger than the sum of its proper divisors (4272097).

21360455 is an equidigital number, since it uses as much as digits as its factorization.

21360455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4272096.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 21360455 is about 4621.7372274936. The cubic root of 21360455 is about 277.4619919267.

Adding to 21360455 its reverse (55406312), we get a palindrome (76766767).

The spelling of 21360455 in words is "twenty-one million, three hundred sixty thousand, four hundred fifty-five".