20471247 has 24 divisors (see below), whose sum is σ = 31792176. Its totient is φ = 12646656.

The previous prime is 20471237. The next prime is 20471261. The reversal of 20471247 is 74217402.

It is a happy number.

It is not a de Polignac number, because 20471247 - 2⁶ = 20471183 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20471247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20471237) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9253 + ... + 11249.

It is an arithmetic number, because the mean of its divisors is an integer number (1324674).

Almost surely, 2^20471247 is an apocalyptic number.

20471247 is a deficient number, since it is larger than the sum of its proper divisors (11320929).

20471247 is a wasteful number, since it uses less digits than its factorization.

20471247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2087 (or 2084 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 20471247 is about 4524.5162172325. The cubic root of 20471247 is about 273.5571682592.

Adding to 20471247 its reverse (74217402), we get a palindrome (94688649).

The spelling of 20471247 in words is "twenty million, four hundred seventy-one thousand, two hundred forty-seven".