21010120021201 has 4 divisors (see below), whose sum is σ = 21015371242404. Its totient is φ = 21004868800000.

The previous prime is 21010120021193. The next prime is 21010120021213. The reversal of 21010120021201 is 10212002101012.

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 10305287734225 + 10704832286976 = 3210185^2 + 3271824^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010120021201 - 2³ = 21010120021193 is a prime.

It is a super-2 number, since 2×21010120021201² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010120021801) 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, 2625604600 + ... + 2625612601.

It is an arithmetic number, because the mean of its divisors is an integer number (5253842810601).

Almost surely, 2^{21010120021201} is an apocalyptic number.

It is an amenable number.

21010120021201 is a deficient number, since it is larger than the sum of its proper divisors (5251221203).

21010120021201 is an equidigital number, since it uses as much as digits as its factorization.

21010120021201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5251221202.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21010120021201 its reverse (10212002101012), we get a palindrome (31222122122213).

The spelling of 21010120021201 in words is "twenty-one trillion, ten billion, one hundred twenty million, twenty-one thousand, two hundred one".