21101220101 has 16 divisors (see below), whose sum is σ = 23107354368. Its totient is φ = 19150084800.

The previous prime is 21101220083. The next prime is 21101220103. The reversal of 21101220101 is 10102210112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101220101 is a prime.

It is a super-2 number, since 2×21101220101² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101220103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2316566 + ... + 2325656.

It is an arithmetic number, because the mean of its divisors is an integer number (1444209648).

Almost surely, 2^21101220101 is an apocalyptic number.

It is an amenable number.

21101220101 is a deficient number, since it is larger than the sum of its proper divisors (2006134267).

21101220101 is a wasteful number, since it uses less digits than its factorization.

21101220101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12092.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21101220101 its reverse (10102210112), we get a palindrome (31203430213).

The spelling of 21101220101 in words is "twenty-one billion, one hundred one million, two hundred twenty thousand, one hundred one".