201010001221 has 4 divisors (see below), whose sum is σ = 202051504012. Its totient is φ = 199968498432.

The previous prime is 201010001173. The next prime is 201010001281. The reversal of 201010001221 is 122100010102.

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 89129117025 + 111880884196 = 298545^2 + 334486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201010001221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201010001198 and 201010001207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201010001281) 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, 520751106 + ... + 520751491.

It is an arithmetic number, because the mean of its divisors is an integer number (50512876003).

Almost surely, 2^201010001221 is an apocalyptic number.

It is an amenable number.

201010001221 is a deficient number, since it is larger than the sum of its proper divisors (1041502791).

201010001221 is a wasteful number, since it uses less digits than its factorization.

201010001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041502790.

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

Adding to 201010001221 its reverse (122100010102), we get a palindrome (323110011323).

The spelling of 201010001221 in words is "two hundred one billion, ten million, one thousand, two hundred twenty-one".