1001012021001 has 24 divisors (see below), whose sum is σ = 1447816545864. Its totient is φ = 666459959040.

The previous prime is 1001012020999. The next prime is 1001012021021. The reversal of 1001012021001 is 1001202101001.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 491288846400 + 509723174601 = 700920^2 + 713949^2 .

It is not a de Polignac number, because 1001012021001 - 2¹ = 1001012020999 is a prime.

It is a super-3 number, since 3×1001012021001³ (a number of 37 digits) contains 333 as substring.

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 (1001012021021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73721725 + ... + 73735301.

It is an arithmetic number, because the mean of its divisors is an integer number (60325689411).

Almost surely, 2^{1001012021001} is an apocalyptic number.

It is an amenable number.

1001012021001 is a deficient number, since it is larger than the sum of its proper divisors (446804524863).

1001012021001 is a wasteful number, since it uses less digits than its factorization.

1001012021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23801 (or 23798 counting only the distinct ones).

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

Adding to 1001012021001 its reverse (1001202101001), we get a palindrome (2002214122002).

The spelling of 1001012021001 in words is "one trillion, one billion, twelve million, twenty-one thousand, one".