2011111021 has 4 divisors (see below), whose sum is σ = 2011337532. Its totient is φ = 2010884512.

The previous prime is 2011111001. The next prime is 2011111043. The reversal of 2011111021 is 1201111102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 43744996 + 1967366025 = 6614^2 + 44355^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2011111021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2011110989 and 2011111007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2011111001) 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, 99370 + ... + 117883.

It is an arithmetic number, because the mean of its divisors is an integer number (502834383).

Almost surely, 2^2011111021 is an apocalyptic number.

It is an amenable number.

2011111021 is a deficient number, since it is larger than the sum of its proper divisors (226511).

2011111021 is an equidigital number, since it uses as much as digits as its factorization.

2011111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226510.

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

The square root of 2011111021 is about 44845.4124855598. The cubic root of 2011111021 is about 1262.2499107414.

Adding to 2011111021 its reverse (1201111102), we get a palindrome (3212222123).

The spelling of 2011111021 in words is "two billion, eleven million, one hundred eleven thousand, twenty-one".