221201100221001 has 4 divisors (see below), whose sum is σ = 294934800294672. Its totient is φ = 147467400147332.

The previous prime is 221201100220981. The next prime is 221201100221009. The reversal of 221201100221001 is 100122001102122.

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 221201100221001 - 2¹⁸ = 221201099958857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221201100221009) 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 3 ways as a sum of consecutive naturals, for example, 36866850036831 + ... + 36866850036836.

It is an arithmetic number, because the mean of its divisors is an integer number (73733700073668).

Almost surely, 2^{221201100221001} is an apocalyptic number.

It is an amenable number.

221201100221001 is a deficient number, since it is larger than the sum of its proper divisors (73733700073671).

221201100221001 is an equidigital number, since it uses as much as digits as its factorization.

221201100221001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73733700073670.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221201100221001 its reverse (100122001102122), we get a palindrome (321323101323123).

The spelling of 221201100221001 in words is "two hundred twenty-one trillion, two hundred one billion, one hundred million, two hundred twenty-one thousand, one".