21001011100101 has 12 divisors (see below), whose sum is σ = 31313335547520. Its totient is φ = 13549039419240.

The previous prime is 21001011100093. The next prime is 21001011100103. The reversal of 21001011100101 is 10100111010012.

It is not a de Polignac number, because 21001011100101 - 2³ = 21001011100093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001011100103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37636220331 + ... + 37636220888.

It is an arithmetic number, because the mean of its divisors is an integer number (2609444628960).

Almost surely, 2^{21001011100101} is an apocalyptic number.

It is an amenable number.

21001011100101 is a deficient number, since it is larger than the sum of its proper divisors (10312324447419).

21001011100101 is a wasteful number, since it uses less digits than its factorization.

21001011100101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75272441256 (or 75272441253 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

Adding to 21001011100101 its reverse (10100111010012), we get a palindrome (31101122110113).

The spelling of 21001011100101 in words is "twenty-one trillion, one billion, eleven million, one hundred thousand, one hundred one".