20709147 has 8 divisors (see below), whose sum is σ = 28503040. Its totient is φ = 13360680.

The previous prime is 20709133. The next prime is 20709203. The reversal of 20709147 is 74190702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20709147 - 2¹⁶ = 20643611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20709127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111247 + ... + 111432.

It is an arithmetic number, because the mean of its divisors is an integer number (3562880).

Almost surely, 2^20709147 is an apocalyptic number.

20709147 is a deficient number, since it is larger than the sum of its proper divisors (7793893).

20709147 is a wasteful number, since it uses less digits than its factorization.

20709147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222713.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 20709147 is about 4550.7303809389. The cubic root of 20709147 is about 274.6127751184.

Adding to 20709147 its reverse (74190702), we get a palindrome (94899849).

The spelling of 20709147 in words is "twenty million, seven hundred nine thousand, one hundred forty-seven".