21101220222001 has 16 divisors (see below), whose sum is σ = 23158404976896. Its totient is φ = 19147308592896.

The previous prime is 21101220221989. The next prime is 21101220222011. The reversal of 21101220222001 is 10022202210112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21101220222001 - 2¹⁹ = 21101219697713 is a prime.

It is a super-2 number, since 2×21101220222001² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21101220222011) 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, 197032566 + ... + 197139631.

It is an arithmetic number, because the mean of its divisors is an integer number (1447400311056).

Almost surely, 2^{21101220222001} is an apocalyptic number.

It is an amenable number.

21101220222001 is a deficient number, since it is larger than the sum of its proper divisors (2057184754895).

21101220222001 is a wasteful number, since it uses less digits than its factorization.

21101220222001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394172328.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21101220222001 its reverse (10022202210112), we get a palindrome (31123422432113).

The spelling of 21101220222001 in words is "twenty-one trillion, one hundred one billion, two hundred twenty million, two hundred twenty-two thousand, one".