1002011220 has 144 divisors (see below), whose sum is σ = 3481470720. Its totient is φ = 228515328.

The previous prime is 1002011201. The next prime is 1002011221. The reversal of 1002011220 is 221102001.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002011221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1018849 + ... + 1019831.

It is an arithmetic number, because the mean of its divisors is an integer number (24176880).

Almost surely, 2^1002011220 is an apocalyptic number.

1002011220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1002011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1740735360).

1002011220 is an abundant number, since it is smaller than the sum of its proper divisors (2479459500).

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

1002011220 is a wasteful number, since it uses less digits than its factorization.

1002011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1814 (or 1809 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1002011220 is about 31654.5608088313. The cubic root of 1002011220 is about 1000.6699577231.

Adding to 1002011220 its reverse (221102001), we get a palindrome (1223113221).

The spelling of 1002011220 in words is "one billion, two million, eleven thousand, two hundred twenty".