1001021111021 has 4 divisors (see below), whose sum is σ = 1001057026812. Its totient is φ = 1000985195232.

The previous prime is 1001021110997. The next prime is 1001021111029. The reversal of 1001021111021 is 1201111201001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 647131758025 + 353889352996 = 804445^2 + 594886^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001021111021 - 2¹⁴ = 1001021094637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1001021110993 and 1001021111011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001021111029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17916056 + ... + 17971841.

It is an arithmetic number, because the mean of its divisors is an integer number (250264256703).

Almost surely, 2^{1001021111021} is an apocalyptic number.

It is an amenable number.

1001021111021 is a deficient number, since it is larger than the sum of its proper divisors (35915791).

1001021111021 is an equidigital number, since it uses as much as digits as its factorization.

1001021111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35915790.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 1001021111021 its reverse (1201111201001), we get a palindrome (2202132312022).

The spelling of 1001021111021 in words is "one trillion, one billion, twenty-one million, one hundred eleven thousand, twenty-one".