20172347 has 6 divisors (see below), whose sum is σ = 21843612. Its totient is φ = 18620472.

The previous prime is 20172343. The next prime is 20172349. The reversal of 20172347 is 74327102.

It is not a de Polignac number, because 20172347 - 2² = 20172343 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20172343) 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, 59513 + ... + 59850.

It is an arithmetic number, because the mean of its divisors is an integer number (3640602).

Almost surely, 2^20172347 is an apocalyptic number.

20172347 is a deficient number, since it is larger than the sum of its proper divisors (1671265).

20172347 is a wasteful number, since it uses less digits than its factorization.

20172347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119389 (or 119376 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 20172347 is about 4491.3636014021. The cubic root of 20172347 is about 272.2192355512.

Adding to 20172347 its reverse (74327102), we get a palindrome (94499449).

The spelling of 20172347 in words is "twenty million, one hundred seventy-two thousand, three hundred forty-seven".