20172305 has 8 divisors (see below), whose sum is σ = 24269544. Its totient is φ = 16096000.

The previous prime is 20172283. The next prime is 20172323. The reversal of 20172305 is 50327102.

It can be written as a sum of positive squares in 4 ways, for example, as 8386816 + 11785489 = 2896^2 + 3433^2 .

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

It is not a de Polignac number, because 20172305 - 2¹² = 20168209 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3026 + ... + 7035.

It is an arithmetic number, because the mean of its divisors is an integer number (3033693).

Almost surely, 2^20172305 is an apocalyptic number.

It is an amenable number.

20172305 is a deficient number, since it is larger than the sum of its proper divisors (4097239).

20172305 is a wasteful number, since it uses less digits than its factorization.

20172305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10467.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 20172305 is about 4491.3589257596. The cubic root of 20172305 is about 272.2190466256.

Adding to 20172305 its reverse (50327102), we get a palindrome (70499407).

The spelling of 20172305 in words is "twenty million, one hundred seventy-two thousand, three hundred five".