201221331021001 has 4 divisors (see below), whose sum is σ = 202263928591252. Its totient is φ = 200178733450752.

The previous prime is 201221331020981. The next prime is 201221331021031. The reversal of 201221331021001 is 100120133122102.

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 112756471129225 + 88464859891776 = 10618685^2 + 9405576^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221331021001 - 2¹⁵ = 201221330988233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 201221331021001.

It is not an unprimeable number, because it can be changed into a prime (201221331021031) 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, 521298784836 + ... + 521298785221.

It is an arithmetic number, because the mean of its divisors is an integer number (50565982147813).

Almost surely, 2^{201221331021001} is an apocalyptic number.

It is an amenable number.

201221331021001 is a deficient number, since it is larger than the sum of its proper divisors (1042597570251).

201221331021001 is a wasteful number, since it uses less digits than its factorization.

201221331021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1042597570250.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 201221331021001 its reverse (100120133122102), we get a palindrome (301341464143103).

The spelling of 201221331021001 in words is "two hundred one trillion, two hundred twenty-one billion, three hundred thirty-one million, twenty-one thousand, one".