21211202101 has 4 divisors (see below), whose sum is σ = 21212965900. Its totient is φ = 21209438304.

The previous prime is 21211202099. The next prime is 21211202119. The reversal of 21211202101 is 10120211212.

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 11534545201 + 9676656900 = 107399^2 + 98370^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211202101 - 2¹ = 21211202099 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 (21211202171) 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, 863736 + ... + 887953.

It is an arithmetic number, because the mean of its divisors is an integer number (5303241475).

Almost surely, 2^21211202101 is an apocalyptic number.

It is an amenable number.

21211202101 is a deficient number, since it is larger than the sum of its proper divisors (1763799).

21211202101 is a wasteful number, since it uses less digits than its factorization.

21211202101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1763798.

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

Adding to 21211202101 its reverse (10120211212), we get a palindrome (31331413313).

The spelling of 21211202101 in words is "twenty-one billion, two hundred eleven million, two hundred two thousand, one hundred one".