20111797 has 4 divisors (see below), whose sum is σ = 20122636. Its totient is φ = 20100960.

The previous prime is 20111789. The next prime is 20111801. The reversal of 20111797 is 79711102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 79711102 = 2 ⋅39855551.

It can be written as a sum of positive squares in 2 ways, for example, as 12680721 + 7431076 = 3561^2 + 2726^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111797 - 2³ = 20111789 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 (20171797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1854 + ... + 6607.

It is an arithmetic number, because the mean of its divisors is an integer number (5030659).

Almost surely, 2^20111797 is an apocalyptic number.

It is an amenable number.

20111797 is a deficient number, since it is larger than the sum of its proper divisors (10839).

20111797 is an equidigital number, since it uses as much as digits as its factorization.

20111797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10838.

The product of its (nonzero) digits is 882, while the sum is 28.

The square root of 20111797 is about 4484.6178209520. The cubic root of 20111797 is about 271.9465950875.

Adding to 20111797 its reverse (79711102), we get a palindrome (99822899).

The spelling of 20111797 in words is "twenty million, one hundred eleven thousand, seven hundred ninety-seven".