1020002021021 has 4 divisors (see below), whose sum is σ = 1020243217500. Its totient is φ = 1019760824544.

The previous prime is 1020002021009. The next prime is 1020002021033. The reversal of 1020002021021 is 1201202000201.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (1020002021009) and next prime (1020002021033).

It can be written as a sum of positive squares in 2 ways, for example, as 522432612025 + 497569408996 = 722795^2 + 705386^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020002021021 - 2⁶ = 1020002020957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020002020993 and 1020002021011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020002021821) 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, 120591896 + ... + 120600353.

It is an arithmetic number, because the mean of its divisors is an integer number (255060804375).

Almost surely, 2^{1020002021021} is an apocalyptic number.

It is an amenable number.

1020002021021 is a deficient number, since it is larger than the sum of its proper divisors (241196479).

1020002021021 is an equidigital number, since it uses as much as digits as its factorization.

1020002021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241196478.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 1020002021021 its reverse (1201202000201), we get a palindrome (2221204021222).

The spelling of 1020002021021 in words is "one trillion, twenty billion, two million, twenty-one thousand, twenty-one".