20101020101021 has 4 divisors (see below), whose sum is σ = 20101048320444. Its totient is φ = 20100991881600.

The previous prime is 20101020100969. The next prime is 20101020101027. The reversal of 20101020101021 is 12010102010102.

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 4124091777796 + 15976928323225 = 2030786^2 + 3997115^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101020101021 - 2⁴² = 15702973589917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20101020100993 and 20101020101011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101020101027) 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, 13012820 + ... + 14475341.

It is an arithmetic number, because the mean of its divisors is an integer number (5025262080111).

Almost surely, 2^{20101020101021} is an apocalyptic number.

It is an amenable number.

20101020101021 is a deficient number, since it is larger than the sum of its proper divisors (28219423).

20101020101021 is an equidigital number, since it uses as much as digits as its factorization.

20101020101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28219422.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20101020101021 its reverse (12010102010102), we get a palindrome (32111122111123).

The spelling of 20101020101021 in words is "twenty trillion, one hundred one billion, twenty million, one hundred one thousand, twenty-one".