21101212212001 has 4 divisors (see below), whose sum is σ = 21101221419712. Its totient is φ = 21101203004292.

The previous prime is 21101212211921. The next prime is 21101212212013. The reversal of 21101212212001 is 10021221210112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21101212212001 - 2¹⁷ = 21101212080929 is a prime.

It is a super-2 number, since 2×21101212212001² (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 (21101212212061) 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, 1841380 + ... + 6752266.

It is an arithmetic number, because the mean of its divisors is an integer number (5275305354928).

Almost surely, 2^{21101212212001} is an apocalyptic number.

It is an amenable number.

21101212212001 is a deficient number, since it is larger than the sum of its proper divisors (9207711).

21101212212001 is an equidigital number, since it uses as much as digits as its factorization.

21101212212001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9207710.

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

Adding to 21101212212001 its reverse (10021221210112), we get a palindrome (31122433422113).

The spelling of 21101212212001 in words is "twenty-one trillion, one hundred one billion, two hundred twelve million, two hundred twelve thousand, one".