21450355 has 4 divisors (see below), whose sum is σ = 25740432. Its totient is φ = 17160280.

The previous prime is 21450353. The next prime is 21450367. The reversal of 21450355 is 55305412.

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

It is not a de Polignac number, because 21450355 - 2¹ = 21450353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21450353) 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, 2145031 + ... + 2145040.

It is an arithmetic number, because the mean of its divisors is an integer number (6435108).

Almost surely, 2^21450355 is an apocalyptic number.

21450355 is a deficient number, since it is larger than the sum of its proper divisors (4290077).

21450355 is an equidigital number, since it uses as much as digits as its factorization.

21450355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4290076.

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 21450355 is about 4631.4527958298. The cubic root of 21450355 is about 277.8506996402.

Adding to 21450355 its reverse (55305412), we get a palindrome (76755767).

The spelling of 21450355 in words is "twenty-one million, four hundred fifty thousand, three hundred fifty-five".