1020111220 has 12 divisors (see below), whose sum is σ = 2142233604. Its totient is φ = 408044480.

The previous prime is 1020111187. The next prime is 1020111263. The reversal of 1020111220 is 221110201.

It can be written as a sum of positive squares in 2 ways, for example, as 328841956 + 691269264 = 18134^2 + 26292^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1020111197 and 1020111206.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25502761 + ... + 25502800.

It is an arithmetic number, because the mean of its divisors is an integer number (178519467).

Almost surely, 2^1020111220 is an apocalyptic number.

1020111220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1020111220 is an abundant number, since it is smaller than the sum of its proper divisors (1122122384).

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

1020111220 is a wasteful number, since it uses less digits than its factorization.

1020111220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51005570 (or 51005568 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1020111220 is about 31939.1800145213. The cubic root of 1020111220 is about 1006.6592953473.

Adding to 1020111220 its reverse (221110201), we get a palindrome (1241221421).

The spelling of 1020111220 in words is "one billion, twenty million, one hundred eleven thousand, two hundred twenty".