20731147 has 6 divisors (see below), whose sum is σ = 21880068. Its totient is φ = 19639692.
The previous prime is 20731133. The next prime is 20731153. The reversal of 20731147 is 74113702.
It is a happy number.
It is not a de Polignac number, because 20731147 - 211 = 20729099 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (20731127) by changing a digit.
It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28353 + ... + 29074.
It is an arithmetic number, because the mean of its divisors is an integer number (3646678).
Almost surely, 220731147 is an apocalyptic number.
20731147 is a deficient number, since it is larger than the sum of its proper divisors (1148921).
20731147 is an equidigital number, since it uses as much as digits as its factorization.
20731147 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 57465 (or 57446 counting only the distinct ones).
The product of its (nonzero) digits is 1176, while the sum is 25.
The square root of 20731147 is about 4553.1469337152. The cubic root of 20731147 is about 274.7099840629.
Adding to 20731147 its reverse (74113702), we get a palindrome (94844849).
The spelling of 20731147 in words is "twenty million, seven hundred thirty-one thousand, one hundred forty-seven".
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