20111111010 has 96 divisors (see below), whose sum is σ = 55439944560. Its totient is φ = 5040635904.

The previous prime is 20111111003. The next prime is 20111111021. The reversal of 20111111010 is 1011111102.

It can be written as a sum of positive squares in 8 ways, for example, as 10997926641 + 9113184369 = 104871^2 + 95463^2 .

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20111110983 and 20111111001.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1168024 + ... + 1185116.

Almost surely, 2^20111111010 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20111111010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27719972280).

20111111010 is an abundant number, since it is smaller than the sum of its proper divisors (35328833550).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20111111010 is a wasteful number, since it uses less digits than its factorization.

20111111010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17892 (or 17889 counting only the distinct ones).

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

Adding to 20111111010 its reverse (1011111102), we get a palindrome (21122222112).

The spelling of 20111111010 in words is "twenty billion, one hundred eleven million, one hundred eleven thousand, ten".