21011220110101 has 16 divisors (see below), whose sum is σ = 22747453424640. Its totient is φ = 19292141148480.

The previous prime is 21011220110099. The next prime is 21011220110129. The reversal of 21011220110101 is 10101102211012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21011220110101 - 2¹ = 21011220110099 is a prime.

It is a super-2 number, since 2×21011220110101² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011220116101) 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, 37995970 + ... + 38544988.

It is an arithmetic number, because the mean of its divisors is an integer number (1421715839040).

Almost surely, 2^{21011220110101} is an apocalyptic number.

It is an amenable number.

21011220110101 is a deficient number, since it is larger than the sum of its proper divisors (1736233314539).

21011220110101 is a wasteful number, since it uses less digits than its factorization.

21011220110101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564636.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21011220110101 its reverse (10101102211012), we get a palindrome (31112322321113).

The spelling of 21011220110101 in words is "twenty-one trillion, eleven billion, two hundred twenty million, one hundred ten thousand, one hundred one".