20405344111 has 4 divisors (see below), whose sum is σ = 20603454352. Its totient is φ = 20207233872.

The previous prime is 20405344049. The next prime is 20405344147. The reversal of 20405344111 is 11144350402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20405344111 - 2¹³ = 20405335919 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 (20405344411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99054966 + ... + 99055171.

It is an arithmetic number, because the mean of its divisors is an integer number (5150863588).

Almost surely, 2^20405344111 is an apocalyptic number.

20405344111 is a deficient number, since it is larger than the sum of its proper divisors (198110241).

20405344111 is a wasteful number, since it uses less digits than its factorization.

20405344111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198110240.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 20405344111 its reverse (11144350402), we get a palindrome (31549694513).

The spelling of 20405344111 in words is "twenty billion, four hundred five million, three hundred forty-four thousand, one hundred eleven".