1020111111 has 32 divisors (see below), whose sum is σ = 1587179520. Its totient is φ = 646300512.

The previous prime is 1020111107. The next prime is 1020111149. The reversal of 1020111111 is 1111110201.

It is not a de Polignac number, because 1020111111 - 2² = 1020111107 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

1020111111 is a modest number, since divided by 11111 gives 10201 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 1020111093 and 1020111102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020111151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92266 + ... + 102728.

It is an arithmetic number, because the mean of its divisors is an integer number (49599360).

Almost surely, 2^1020111111 is an apocalyptic number.

1020111111 is a deficient number, since it is larger than the sum of its proper divisors (567068409).

1020111111 is a wasteful number, since it uses less digits than its factorization.

1020111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10652 (or 10646 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

The square root of 1020111111 is about 31939.1783081531. The cubic root of 1020111111 is about 1006.6592594931.

Adding to 1020111111 its reverse (1111110201), we get a palindrome (2131221312).

It can be divided in two parts, 10201 and 11111, that multiplied together give a palindrome (113343311).

The spelling of 1020111111 in words is "one billion, twenty million, one hundred eleven thousand, one hundred eleven".