221010000021001 has 4 divisors (see below), whose sum is σ = 221301955107652. Its totient is φ = 220718044934352.

The previous prime is 221010000020969. The next prime is 221010000021047. The reversal of 221010000021001 is 100120000010122.

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 65443650575625 + 155566349445376 = 8089725^2 + 12472624^2 .

It is a cyclic number.

It is not a de Polignac number, because 221010000021001 - 2⁵ = 221010000020969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221010000022001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145977542190 + ... + 145977543703.

It is an arithmetic number, because the mean of its divisors is an integer number (55325488776913).

Almost surely, 2^{221010000021001} is an apocalyptic number.

It is an amenable number.

221010000021001 is a deficient number, since it is larger than the sum of its proper divisors (291955086651).

221010000021001 is an equidigital number, since it uses as much as digits as its factorization.

221010000021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291955086650.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 221010000021001 its reverse (100120000010122), we get a palindrome (321130000031123).

The spelling of 221010000021001 in words is "two hundred twenty-one trillion, ten billion, twenty-one thousand, one".