1021013200021 has 4 divisors (see below), whose sum is σ = 1021151312812. Its totient is φ = 1020875087232.

The previous prime is 1021013200013. The next prime is 1021013200079. The reversal of 1021013200021 is 1200023101201.

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 311602869796 + 709410330225 = 558214^2 + 842265^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021013200021 - 2³ = 1021013200013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021013199974 and 1021013200010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021013200121) 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, 69045306 + ... + 69060091.

It is an arithmetic number, because the mean of its divisors is an integer number (255287828203).

Almost surely, 2^{1021013200021} is an apocalyptic number.

It is an amenable number.

1021013200021 is a deficient number, since it is larger than the sum of its proper divisors (138112791).

1021013200021 is an equidigital number, since it uses as much as digits as its factorization.

1021013200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138112790.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 1021013200021 its reverse (1200023101201), we get a palindrome (2221036301222).

The spelling of 1021013200021 in words is "one trillion, twenty-one billion, thirteen million, two hundred thousand, twenty-one".