20409147 has 12 divisors (see below), whose sum is σ = 32160024. Its totient is φ = 12369120.

The previous prime is 20409131. The next prime is 20409149. The reversal of 20409147 is 74190402.

It is a happy number.

It is not a de Polignac number, because 20409147 - 2⁴ = 20409131 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20409147.

It is not an unprimeable number, because it can be changed into a prime (20409149) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 102978 + ... + 103175.

It is an arithmetic number, because the mean of its divisors is an integer number (2680002).

Almost surely, 2^20409147 is an apocalyptic number.

20409147 is a deficient number, since it is larger than the sum of its proper divisors (11750877).

20409147 is a wasteful number, since it uses less digits than its factorization.

20409147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206170 (or 206167 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20409147 is about 4517.6483926928. The cubic root of 20409147 is about 273.2802740884.

Adding to 20409147 its reverse (74190402), we get a palindrome (94599549).

The spelling of 20409147 in words is "twenty million, four hundred nine thousand, one hundred forty-seven".