1000001121021 has 24 divisors (see below), whose sum is σ = 1651846457664. Its totient is φ = 571065419520.

The previous prime is 1000001121019. The next prime is 1000001121079. The reversal of 1000001121021 is 1201211000001.

It is a happy number.

It is not a de Polignac number, because 1000001121021 - 2¹ = 1000001121019 is a prime.

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 = 1000001120994 and 1000001121012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000001121521) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 4952916 + ... + 5150861.

It is an arithmetic number, because the mean of its divisors is an integer number (68826935736).

Almost surely, 2^{1000001121021} is an apocalyptic number.

It is an amenable number.

1000001121021 is a deficient number, since it is larger than the sum of its proper divisors (651845336643).

1000001121021 is a wasteful number, since it uses less digits than its factorization.

1000001121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10105361 (or 10105358 counting only the distinct ones).

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

Adding to 1000001121021 its reverse (1201211000001), we get a palindrome (2201212121022).

The spelling of 1000001121021 in words is "one trillion, one million, one hundred twenty-one thousand, twenty-one".