1001012021100 has 720 divisors, whose sum is σ = 4131507441600. Its totient is φ = 203915335680.

The previous prime is 1001012021089. The next prime is 1001012021167. The reversal of 1001012021100 is 11202101001.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 21352486 + ... + 21399314.

It is an arithmetic number, because the mean of its divisors is an integer number (5738204780).

Almost surely, 2^{1001012021100} is an apocalyptic number.

1001012021100 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 1001012021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2065753720800).

1001012021100 is an abundant number, since it is smaller than the sum of its proper divisors (3130495420500).

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

1001012021100 is a wasteful number, since it uses less digits than its factorization.

1001012021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46904 (or 46888 counting only the distinct ones).

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

Adding to 1001012021100 its reverse (11202101001), we get a palindrome (1012214122101).

The spelling of 1001012021100 in words is "one trillion, one billion, twelve million, twenty-one thousand, one hundred".