21450361 has 4 divisors (see below), whose sum is σ = 21473424. Its totient is φ = 21427300.

The previous prime is 21450353. The next prime is 21450367. The reversal of 21450361 is 16305412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21450361 - 2³ = 21450353 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21450367) 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, 10075 + ... + 12016.

It is an arithmetic number, because the mean of its divisors is an integer number (5368356).

Almost surely, 2^21450361 is an apocalyptic number.

It is an amenable number.

21450361 is a deficient number, since it is larger than the sum of its proper divisors (23063).

21450361 is an equidigital number, since it uses as much as digits as its factorization.

21450361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23062.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21450361 is about 4631.4534435747. The cubic root of 21450361 is about 277.8507255466.

Adding to 21450361 its reverse (16305412), we get a palindrome (37755773).

The spelling of 21450361 in words is "twenty-one million, four hundred fifty thousand, three hundred sixty-one".