21101212012201 has 4 divisors (see below), whose sum is σ = 21101297764804. Its totient is φ = 21101126259600.

The previous prime is 21101212012187. The next prime is 21101212012219. The reversal of 21101212012201 is 10221021210112.

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 5324833153600 + 15776378858601 = 2307560^2 + 3971949^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101212012201 - 2⁹ = 21101212011689 is a prime.

It is a super-2 number, since 2×21101212012201² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101212012261) 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, 42506130 + ... + 42999691.

It is an arithmetic number, because the mean of its divisors is an integer number (5275324441201).

Almost surely, 2^{21101212012201} is an apocalyptic number.

It is an amenable number.

21101212012201 is a deficient number, since it is larger than the sum of its proper divisors (85752603).

21101212012201 is an equidigital number, since it uses as much as digits as its factorization.

21101212012201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85752602.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21101212012201 its reverse (10221021210112), we get a palindrome (31322233222313).

The spelling of 21101212012201 in words is "twenty-one trillion, one hundred one billion, two hundred twelve million, twelve thousand, two hundred one".