20111020111001 has 4 divisors (see below), whose sum is σ = 20269374600192. Its totient is φ = 19952665621812.

The previous prime is 20111020110971. The next prime is 20111020111087. The reversal of 20111020111001 is 10011102011102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20111020111001 is a prime.

It is a super-2 number, since 2×20111020111001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20111020111601) 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, 79177244405 + ... + 79177244658.

It is an arithmetic number, because the mean of its divisors is an integer number (5067343650048).

Almost surely, 2^{20111020111001} is an apocalyptic number.

It is an amenable number.

20111020111001 is a deficient number, since it is larger than the sum of its proper divisors (158354489191).

20111020111001 is a wasteful number, since it uses less digits than its factorization.

20111020111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158354489190.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 20111020111001 its reverse (10011102011102), we get a palindrome (30122122122103).

The spelling of 20111020111001 in words is "twenty trillion, one hundred eleven billion, twenty million, one hundred eleven thousand, one".