1001011021200 has 180 divisors, whose sum is σ = 3539330114580. Its totient is φ = 261899688960.

The previous prime is 1001011021187. The next prime is 1001011021207. The reversal of 1001011021200 is 21201101001.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 19675111824 + 981335909376 = 140268^2 + 990624^2 .

It is a tau number, because it is divible by the number of its divisors (180).

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

It is not an unprimeable number, because it can be changed into a prime (1001011021207) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2432395 + ... + 2813994.

It is an arithmetic number, because the mean of its divisors is an integer number (19662945081).

Almost surely, 2^{1001011021200} is an apocalyptic number.

1001011021200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1001011021200 is an abundant number, since it is smaller than the sum of its proper divisors (2538319093380).

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

1001011021200 is a wasteful number, since it uses less digits than its factorization.

1001011021200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5246466 (or 5246452 counting only the distinct ones).

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

Adding to 1001011021200 its reverse (21201101001), we get a palindrome (1022212122201).

The spelling of 1001011021200 in words is "one trillion, one billion, eleven million, twenty-one thousand, two hundred".