21001331201 has 4 divisors (see below), whose sum is σ = 21057635412. Its totient is φ = 20945026992.

The previous prime is 21001331189. The next prime is 21001331209. The reversal of 21001331201 is 10213310012.

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 3878300176 + 17123031025 = 62276^2 + 130855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001331201 is a prime.

It is a super-2 number, since 2×21001331201² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001331209) 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, 28151546 + ... + 28152291.

It is an arithmetic number, because the mean of its divisors is an integer number (5264408853).

Almost surely, 2^21001331201 is an apocalyptic number.

It is an amenable number.

21001331201 is a deficient number, since it is larger than the sum of its proper divisors (56304211).

21001331201 is an equidigital number, since it uses as much as digits as its factorization.

21001331201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56304210.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21001331201 its reverse (10213310012), we get a palindrome (31214641213).

The spelling of 21001331201 in words is "twenty-one billion, one million, three hundred thirty-one thousand, two hundred one".