20101111021 has 4 divisors (see below), whose sum is σ = 20117441344. Its totient is φ = 20084780700.

The previous prime is 20101111007. The next prime is 20101111031. The reversal of 20101111021 is 12011110102.

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 not a de Polignac number, because 20101111021 - 2¹⁷ = 20100979949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20101110989 and 20101111007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101111031) 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, 8163315 + ... + 8165776.

It is an arithmetic number, because the mean of its divisors is an integer number (5029360336).

Almost surely, 2^20101111021 is an apocalyptic number.

It is an amenable number.

20101111021 is a deficient number, since it is larger than the sum of its proper divisors (16330323).

20101111021 is a wasteful number, since it uses less digits than its factorization.

20101111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16330322.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 20101111021 its reverse (12011110102), we get a palindrome (32112221123).

The spelling of 20101111021 in words is "twenty billion, one hundred one million, one hundred eleven thousand, twenty-one".