21101200101021 has 16 divisors (see below), whose sum is σ = 28898128582784. Its totient is φ = 13685942637504.

The previous prime is 21101200101011. The next prime is 21101200101029. The reversal of 21101200101021 is 12010100210112.

It is not a de Polignac number, because 21101200101021 - 2¹⁰ = 21101200099997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101200100988 and 21101200101006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101200101029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8027785 + ... + 10327038.

It is an arithmetic number, because the mean of its divisors is an integer number (1806133036424).

Almost surely, 2^{21101200101021} is an apocalyptic number.

It is an amenable number.

21101200101021 is a deficient number, since it is larger than the sum of its proper divisors (7796928481763).

21101200101021 is a wasteful number, since it uses less digits than its factorization.

21101200101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18365220.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21101200101021 its reverse (12010100210112), we get a palindrome (33111300311133).

The spelling of 21101200101021 in words is "twenty-one trillion, one hundred one billion, two hundred million, one hundred one thousand, twenty-one".