21101001210101 has 4 divisors (see below), whose sum is σ = 21235402491852. Its totient is φ = 20966599928352.

The previous prime is 21101001210097. The next prime is 21101001210119. The reversal of 21101001210101 is 10101210010112.

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 13624883616100 + 7476117594001 = 3691190^2 + 2734249^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101001210101 - 2² = 21101001210097 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 (21101001210901) 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, 67200640640 + ... + 67200640953.

It is an arithmetic number, because the mean of its divisors is an integer number (5308850622963).

Almost surely, 2^{21101001210101} is an apocalyptic number.

It is an amenable number.

21101001210101 is a deficient number, since it is larger than the sum of its proper divisors (134401281751).

21101001210101 is a wasteful number, since it uses less digits than its factorization.

21101001210101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134401281750.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21101001210101 its reverse (10101210010112), we get a palindrome (31202211220213).

The spelling of 21101001210101 in words is "twenty-one trillion, one hundred one billion, one million, two hundred ten thousand, one hundred one".