21111001222001 has 4 divisors (see below), whose sum is σ = 21111026129472. Its totient is φ = 21110976314532.

The previous prime is 21111001221977. The next prime is 21111001222007. The reversal of 21111001222001 is 10022210011112.

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.

It is a cyclic number.

It is not a de Polignac number, because 21111001222001 - 2¹⁰ = 21111001220977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111001222007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11135885 + ... + 12893018.

It is an arithmetic number, because the mean of its divisors is an integer number (5277756532368).

Almost surely, 2^{21111001222001} is an apocalyptic number.

It is an amenable number.

21111001222001 is a deficient number, since it is larger than the sum of its proper divisors (24907471).

21111001222001 is an equidigital number, since it uses as much as digits as its factorization.

21111001222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24907470.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21111001222001 its reverse (10022210011112), we get a palindrome (31133211233113).

The spelling of 21111001222001 in words is "twenty-one trillion, one hundred eleven billion, one million, two hundred twenty-two thousand, one".