21010220101 has 6 divisors (see below), whose sum is σ = 22750711890. Its totient is φ = 19394049168.

The previous prime is 21010220089. The next prime is 21010220129. The reversal of 21010220101 is 10102201012.

It can be written as a sum of positive squares in 3 ways, for example, as 61999876 + 20948220225 = 7874^2 + 144735^2 .

It is not a de Polignac number, because 21010220101 - 2⁷ = 21010219973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010220171) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62160246 + ... + 62160583.

It is an arithmetic number, because the mean of its divisors is an integer number (3791785315).

Almost surely, 2^21010220101 is an apocalyptic number.

It is an amenable number.

21010220101 is a deficient number, since it is larger than the sum of its proper divisors (1740491789).

21010220101 is a wasteful number, since it uses less digits than its factorization.

21010220101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124320855 (or 124320842 counting only the distinct ones).

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

Adding to 21010220101 its reverse (10102201012), we get a palindrome (31112421113).

It can be divided in two parts, 2 and 1010220101, that multiplied together give a palindrome (2020440202).

The spelling of 21010220101 in words is "twenty-one billion, ten million, two hundred twenty thousand, one hundred one".