1001231320021 has 4 divisors (see below), whose sum is σ = 1022534114112. Its totient is φ = 979928525932.

The previous prime is 1001231320009. The next prime is 1001231320093. The reversal of 1001231320021 is 1200231321001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1001231320021 - 2⁵ = 1001231319989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1001231319977 and 1001231320004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001231320421) 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 3 ways as a sum of consecutive naturals, for example, 10651396975 + ... + 10651397068.

It is an arithmetic number, because the mean of its divisors is an integer number (255633528528).

Almost surely, 2^{1001231320021} is an apocalyptic number.

It is an amenable number.

1001231320021 is a deficient number, since it is larger than the sum of its proper divisors (21302794091).

1001231320021 is an equidigital number, since it uses as much as digits as its factorization.

1001231320021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21302794090.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 1001231320021 its reverse (1200231321001), we get a palindrome (2201462641022).

The spelling of 1001231320021 in words is "one trillion, one billion, two hundred thirty-one million, three hundred twenty thousand, twenty-one".