221220012001 has 4 divisors (see below), whose sum is σ = 222137937604. Its totient is φ = 220302086400.

The previous prime is 221220011959. The next prime is 221220012061. The reversal of 221220012001 is 100210022122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 158146200976 + 63073811025 = 397676^2 + 251145^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220012001 - 2¹⁷ = 221219880929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221220012061) 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, 458962440 + ... + 458962921.

It is an arithmetic number, because the mean of its divisors is an integer number (55534484401).

Almost surely, 2^221220012001 is an apocalyptic number.

It is an amenable number.

221220012001 is a deficient number, since it is larger than the sum of its proper divisors (917925603).

221220012001 is an equidigital number, since it uses as much as digits as its factorization.

221220012001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917925602.

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

Adding to 221220012001 its reverse (100210022122), we get a palindrome (321430034123).

The spelling of 221220012001 in words is "two hundred twenty-one billion, two hundred twenty million, twelve thousand, one".