10101020021 has 2 divisors, whose sum is σ = 10101020022. Its totient is φ = 10101020020.

The previous prime is 10101019969. The next prime is 10101020029. The reversal of 10101020021 is 12002010101.

It is an a-pointer prime, because the next prime (10101020029) can be obtained adding 10101020021 to its sum of digits (8).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10090202500 + 10817521 = 100450^2 + 3289^2 .

It is an emirp because it is prime and its reverse (12002010101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10101020021 - 2²⁶ = 10033911157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 10101019990 and 10101020008.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10101020029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5050510010 + 5050510011.

It is an arithmetic number, because the mean of its divisors is an integer number (5050510011).

Almost surely, 2^10101020021 is an apocalyptic number.

It is an amenable number.

10101020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

10101020021 is an equidigital number, since it uses as much as digits as its factorization.

10101020021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 10101020021 its reverse (12002010101), we get a palindrome (22103030122).

The spelling of 10101020021 in words is "ten billion, one hundred one million, twenty thousand, twenty-one".