20305147 has 4 divisors (see below), whose sum is σ = 20386296. Its totient is φ = 20224000.

The previous prime is 20305097. The next prime is 20305151. The reversal of 20305147 is 74150302.

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 20305147 - 2¹⁵ = 20272379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20305247) 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, 40198 + ... + 40699.

It is an arithmetic number, because the mean of its divisors is an integer number (5096574).

Almost surely, 2^20305147 is an apocalyptic number.

20305147 is a deficient number, since it is larger than the sum of its proper divisors (81149).

20305147 is an equidigital number, since it uses as much as digits as its factorization.

20305147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81148.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 20305147 is about 4506.1232783846. The cubic root of 20305147 is about 272.8152936662.

Adding to 20305147 its reverse (74150302), we get a palindrome (94455449).

The spelling of 20305147 in words is "twenty million, three hundred five thousand, one hundred forty-seven".