1001220100020 has 144 divisors (see below), whose sum is σ = 3490287615360. Its totient is φ = 227571763968.

The previous prime is 1001220099967. The next prime is 1001220100057. The reversal of 1001220100020 is 200010221001.

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

It is a junction number, because it is equal to n+sod(n) for n = 1001220099975 and 1001220100011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1994067 + ... + 2445146.

It is an arithmetic number, because the mean of its divisors is an integer number (24238108440).

Almost surely, 2^{1001220100020} is an apocalyptic number.

1001220100020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1001220100020 is an abundant number, since it is smaller than the sum of its proper divisors (2489067515340).

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

1001220100020 is a wasteful number, since it uses less digits than its factorization.

1001220100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4439414 (or 4439409 counting only the distinct ones).

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

Adding to 1001220100020 its reverse (200010221001), we get a palindrome (1201230321021).

The spelling of 1001220100020 in words is "one trillion, one billion, two hundred twenty million, one hundred thousand, twenty".