1001012220 has 144 divisors (see below), whose sum is σ = 3292790592. Its totient is φ = 244684800.

The previous prime is 1001012203. The next prime is 1001012237. The reversal of 1001012220 is 222101001.

It is an interprime number because it is at equal distance from previous prime (1001012203) and next prime (1001012237).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 351924 + ... + 354756.

Almost surely, 2^1001012220 is an apocalyptic number.

1001012220 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 1001012220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1646395296).

1001012220 is an abundant number, since it is smaller than the sum of its proper divisors (2291778372).

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

1001012220 is a wasteful number, since it uses less digits than its factorization.

1001012220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3012 (or 3007 counting only the distinct ones).

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

The square root of 1001012220 is about 31638.7771571532. Note that the first 3 decimals coincide. The cubic root of 1001012220 is about 1000.3372928874.

Adding to 1001012220 its reverse (222101001), we get a palindrome (1223113221).

The spelling of 1001012220 in words is "one billion, one million, twelve thousand, two hundred twenty".