21010220210101 has 4 divisors (see below), whose sum is σ = 21010259817100. Its totient is φ = 21010180603104.

The previous prime is 21010220210087. The next prime is 21010220210107. The reversal of 21010220210101 is 10101202201012.

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 1113499800625 + 19896720409476 = 1055225^2 + 4460574^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010220210101 - 2²⁵ = 21010186655669 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 (21010220210107) 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, 18996846 + ... + 20072383.

It is an arithmetic number, because the mean of its divisors is an integer number (5252564954275).

Almost surely, 2^{21010220210101} is an apocalyptic number.

It is an amenable number.

21010220210101 is a deficient number, since it is larger than the sum of its proper divisors (39606999).

21010220210101 is an equidigital number, since it uses as much as digits as its factorization.

21010220210101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39606998.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21010220210101 its reverse (10101202201012), we get a palindrome (31111422411113).

The spelling of 21010220210101 in words is "twenty-one trillion, ten billion, two hundred twenty million, two hundred ten thousand, one hundred one".