21450271 has 4 divisors (see below), whose sum is σ = 21708792. Its totient is φ = 21191752.

The previous prime is 21450241. The next prime is 21450293. The reversal of 21450271 is 17205412.

It is a happy number.

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 21450271 - 2⁵ = 21450239 is a prime.

It is a super-2 number, since 2×21450271² = 920228251946882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450211) 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, 129136 + ... + 129301.

It is an arithmetic number, because the mean of its divisors is an integer number (5427198).

Almost surely, 2^21450271 is an apocalyptic number.

21450271 is a deficient number, since it is larger than the sum of its proper divisors (258521).

21450271 is an equidigital number, since it uses as much as digits as its factorization.

21450271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258520.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21450271 is about 4631.4437273921. The cubic root of 21450271 is about 277.8503369501.

Adding to 21450271 its reverse (17205412), we get a palindrome (38655683).

The spelling of 21450271 in words is "twenty-one million, four hundred fifty thousand, two hundred seventy-one".