2021001002021 has 4 divisors (see below), whose sum is σ = 2021021695500. Its totient is φ = 2020980308544.

The previous prime is 2021001001973. The next prime is 2021001002023. The reversal of 2021001002021 is 1202001001202.

It is a happy number.

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 324791709025 + 1696209292996 = 569905^2 + 1302386^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021001002021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021001001993 and 2021001002011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021001002023) 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, 10199546 + ... + 10395803.

It is an arithmetic number, because the mean of its divisors is an integer number (505255423875).

Almost surely, 2^{2021001002021} is an apocalyptic number.

It is an amenable number.

2021001002021 is a deficient number, since it is larger than the sum of its proper divisors (20693479).

2021001002021 is an equidigital number, since it uses as much as digits as its factorization.

2021001002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20693478.

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

Adding to 2021001002021 its reverse (1202001001202), we get a palindrome (3223002003223).

The spelling of 2021001002021 in words is "two trillion, twenty-one billion, one million, two thousand, twenty-one".