20440471 has 4 divisors (see below), whose sum is σ = 20470744. Its totient is φ = 20410200.

The previous prime is 20440423. The next prime is 20440487. The reversal of 20440471 is 17404402.

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 20440471 - 2⁹ = 20439959 is a prime.

It is a super-3 number, since 3×20440471³ (a number of 23 digits) contains 333 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 (20440421) 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, 14100 + ... + 15481.

It is an arithmetic number, because the mean of its divisors is an integer number (5117686).

Almost surely, 2^20440471 is an apocalyptic number.

20440471 is a deficient number, since it is larger than the sum of its proper divisors (30273).

20440471 is an equidigital number, since it uses as much as digits as its factorization.

20440471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30272.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 20440471 is about 4521.1139114161. The cubic root of 20440471 is about 273.4200129943.

Adding to 20440471 its reverse (17404402), we get a palindrome (37844873).

The spelling of 20440471 in words is "twenty million, four hundred forty thousand, four hundred seventy-one".