20581197 has 16 divisors (see below), whose sum is σ = 33774720. Its totient is φ = 10855872.

The previous prime is 20581189. The next prime is 20581201. The reversal of 20581197 is 79118502.

It is not a de Polignac number, because 20581197 - 2³ = 20581189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20582197) 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, 37422 + ... + 37967.

It is an arithmetic number, because the mean of its divisors is an integer number (2110920).

Almost surely, 2^20581197 is an apocalyptic number.

It is an amenable number.

20581197 is a deficient number, since it is larger than the sum of its proper divisors (13193523).

20581197 is a wasteful number, since it uses less digits than its factorization.

20581197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75412.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 20581197 is about 4536.6504163314. The cubic root of 20581197 is about 274.0460478135.

Adding to 20581197 its reverse (79118502), we get a palindrome (99699699).

The spelling of 20581197 in words is "twenty million, five hundred eighty-one thousand, one hundred ninety-seven".