20731197 has 16 divisors (see below), whose sum is σ = 28228928. Its totient is φ = 13530240.

The previous prime is 20731189. The next prime is 20731231. The reversal of 20731197 is 79113702.

It is not a de Polignac number, because 20731197 - 2³ = 20731189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39378 + ... + 39900.

It is an arithmetic number, because the mean of its divisors is an integer number (1764308).

Almost surely, 2^20731197 is an apocalyptic number.

It is an amenable number.

20731197 is a deficient number, since it is larger than the sum of its proper divisors (7497731).

20731197 is a wasteful number, since it uses less digits than its factorization.

20731197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780.

The product of its (nonzero) digits is 2646, while the sum is 30.

The square root of 20731197 is about 4553.1524244198. The cubic root of 20731197 is about 274.7102049140.

Adding to 20731197 its reverse (79113702), we get a palindrome (99844899).

The spelling of 20731197 in words is "twenty million, seven hundred thirty-one thousand, one hundred ninety-seven".