20001021100021 has 8 divisors (see below), whose sum is σ = 21543232574304. Its totient is φ = 18459334110000.

The previous prime is 20001021100019. The next prime is 20001021100061. The reversal of 20001021100021 is 12000112010002.

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 20001021100021 - 2¹ = 20001021100019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20001021099980 and 20001021100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001021100061) 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, 131041855 + ... + 131194396.

It is an arithmetic number, because the mean of its divisors is an integer number (2692904071788).

Almost surely, 2^{20001021100021} is an apocalyptic number.

It is an amenable number.

20001021100021 is a deficient number, since it is larger than the sum of its proper divisors (1542211474283).

20001021100021 is a wasteful number, since it uses less digits than its factorization.

20001021100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262242131.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20001021100021 its reverse (12000112010002), we get a palindrome (32001133110023).

The spelling of 20001021100021 in words is "twenty trillion, one billion, twenty-one million, one hundred thousand, twenty-one".