1001001011220 has 144 divisors (see below), whose sum is σ = 3472581665280. Its totient is φ = 228639034368.

The previous prime is 1001001011137. The next prime is 1001001011239. The reversal of 1001001011220 is 221101001001.

It is a happy number.

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, 1513836 + ... + 2072124.

Almost surely, 2^{1001001011220} is an apocalyptic number.

1001001011220 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 1001001011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1736290832640).

1001001011220 is an abundant number, since it is smaller than the sum of its proper divisors (2471580654060).

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

1001001011220 is a wasteful number, since it uses less digits than its factorization.

1001001011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559734 (or 559729 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1001001011220 its reverse (221101001001), we get a palindrome (1222102012221).

The spelling of 1001001011220 in words is "one trillion, one billion, one million, eleven thousand, two hundred twenty".