2011531111 has 4 divisors (see below), whose sum is σ = 2011691824. Its totient is φ = 2011370400.

The previous prime is 2011531057. The next prime is 2011531129. The reversal of 2011531111 is 1111351102.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2011531111 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 (2011531811) 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, 59835 + ... + 87196.

It is an arithmetic number, because the mean of its divisors is an integer number (502922956).

Almost surely, 2^2011531111 is an apocalyptic number.

2011531111 is a deficient number, since it is larger than the sum of its proper divisors (160713).

2011531111 is a wasteful number, since it uses less digits than its factorization.

2011531111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160712.

The product of its (nonzero) digits is 30, while the sum is 16.

The square root of 2011531111 is about 44850.0959976676. The cubic root of 2011531111 is about 1262.3377927865.

Adding to 2011531111 its reverse (1111351102), we get a palindrome (3122882213).

Subtracting from 2011531111 its reverse (1111351102), we obtain a square (900180009 = 30003²).

The spelling of 2011531111 in words is "two billion, eleven million, five hundred thirty-one thousand, one hundred eleven".