201243121 has 4 divisors (see below), whose sum is σ = 201422500. Its totient is φ = 201063744.

The previous prime is 201243113. The next prime is 201243131. The reversal of 201243121 is 121342102.

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 109830400 + 91412721 = 10480^2 + 9561^2 .

It is a cyclic number.

It is not a de Polignac number, because 201243121 - 2³ = 201243113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201243095 and 201243104.

It is not an unprimeable number, because it can be changed into a prime (201243101) 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, 87996 + ... + 90253.

It is an arithmetic number, because the mean of its divisors is an integer number (50355625).

Almost surely, 2^201243121 is an apocalyptic number.

It is an amenable number.

201243121 is a deficient number, since it is larger than the sum of its proper divisors (179379).

201243121 is a wasteful number, since it uses less digits than its factorization.

201243121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179378.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 201243121 is about 14186.0185041470. The cubic root of 201243121 is about 586.0126818768.

Adding to 201243121 its reverse (121342102), we get a palindrome (322585223).

The spelling of 201243121 in words is "two hundred one million, two hundred forty-three thousand, one hundred twenty-one".