221001101000021 has 8 divisors (see below), whose sum is σ = 221070139028184. Its totient is φ = 220932072806400.

The previous prime is 221001101000011. The next prime is 221001101000023. The reversal of 221001101000021 is 120000101100122.

It can be written as a sum of positive squares in 4 ways, for example, as 11525006522500 + 209476094477521 = 3394850^2 + 14473289^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221001101000021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221001100999966 and 221001101000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001101000023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42621221 + ... + 47524421.

It is an arithmetic number, because the mean of its divisors is an integer number (27633767378523).

Almost surely, 2^{221001101000021} is an apocalyptic number.

It is an amenable number.

221001101000021 is a deficient number, since it is larger than the sum of its proper divisors (69038028163).

221001101000021 is an equidigital number, since it uses as much as digits as its factorization.

221001101000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4917271.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 221001101000021 its reverse (120000101100122), we get a palindrome (341001202100143).

The spelling of 221001101000021 in words is "two hundred twenty-one trillion, one billion, one hundred one million, twenty-one", and thus it is an aban number.