20001020111 has 4 divisors (see below), whose sum is σ = 21053705400. Its totient is φ = 18948334824.

The previous prime is 20001020099. The next prime is 20001020113. The reversal of 20001020111 is 11102010002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11102010002 = 2 ⋅5551005001.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001020111 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 (20001020113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 526342616 + ... + 526342653.

It is an arithmetic number, because the mean of its divisors is an integer number (5263426350).

Almost surely, 2^20001020111 is an apocalyptic number.

20001020111 is a deficient number, since it is larger than the sum of its proper divisors (1052685289).

20001020111 is a wasteful number, since it uses less digits than its factorization.

20001020111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1052685288.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 20001020111 its reverse (11102010002), we get a palindrome (31103030113).

The spelling of 20001020111 in words is "twenty billion, one million, twenty thousand, one hundred eleven".