221021220001 has 4 divisors (see below), whose sum is σ = 222255975600. Its totient is φ = 219786464404.

The previous prime is 221021219999. The next prime is 221021220023. The reversal of 221021220001 is 100022120122.

It is a happy number.

221021220001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 221021220001 - 2¹ = 221021219999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221021220031) 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, 617377531 + ... + 617377888.

It is an arithmetic number, because the mean of its divisors is an integer number (55563993900).

Almost surely, 2^221021220001 is an apocalyptic number.

It is an amenable number.

221021220001 is a deficient number, since it is larger than the sum of its proper divisors (1234755599).

221021220001 is a wasteful number, since it uses less digits than its factorization.

221021220001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234755598.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 221021220001 its reverse (100022120122), we get a palindrome (321043340123).

The spelling of 221021220001 in words is "two hundred twenty-one billion, twenty-one million, two hundred twenty thousand, one".