2021020100021 has 8 divisors (see below), whose sum is σ = 2192369925144. Its totient is φ = 1851939809280.

The previous prime is 2021020100009. The next prime is 2021020100041. The reversal of 2021020100021 is 1200010201202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1534680625 + 2019485419396 = 39175^2 + 1421086^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2021020100021 - 2³⁸ = 1746142193077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021020099975 and 2021020100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021020100041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 567381740 + ... + 567385301.

It is an arithmetic number, because the mean of its divisors is an integer number (274046240643).

Almost surely, 2^{2021020100021} is an apocalyptic number.

It is an amenable number.

2021020100021 is a deficient number, since it is larger than the sum of its proper divisors (171349825123).

2021020100021 is a wasteful number, since it uses less digits than its factorization.

2021020100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1134767191.

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

Adding to 2021020100021 its reverse (1200010201202), we get a palindrome (3221030301223).

The spelling of 2021020100021 in words is "two trillion, twenty-one billion, twenty million, one hundred thousand, twenty-one".